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Please some help to integrate trasfere relay


Francesco 2021/10/30 13:53

Hello all, please there is someone to help me to integrate one USB relay board for the transfer relay on Johe Smith NanoVNA software? I read on the manual and I don't quite and standing for my ignorance on USB soft/hardware system.
The manual quote: *The software really doesn’t care what type of transfer relay is attached. It uses a common USB – TTL adapter from FTDI. The RTS signal is used to select the state of the relay and the CTS is used to monitor it’s status. The communications port is selected in the Setup/Diagnostics page using the XferPort. Again, the BAUD rate has no effect. The selected port is saved as part of the defaults. Shown is the FTDI cable attached to the Transco controller.
*
*19.1 Manually Controlling the Transfer Relay With the correct communications port selected, the next time Link is selected, the software will check for the presence of the port. There is no other check beyond it finding a valid port number. If found the XferRly Lnk indicator (found on the main page), will become active. You can manually change the state of the relay by selecting the CH0-A switch on the front panel. Once selected, the Chan0-B indicator will become active. If the relay does not change states, the XferRly Err indicator will become active.
*
*The USB – TTL adapter from FTDI. are some think like this board?*

John Galbreath 2021/10/30 17:56

please show link to specification of this board.
looks like you are headed in right direction.

Jim Lux 2021/10/30 18:12

On 10/30/21 5:56 PM, John Galbreath via groups.io wrote:
> please show link to specification of this board.
> looks like you are headed in right direction.
> _._,_


I've been fooling with USB relay boards recently, and there's *multiple*
FTDI chips that get used.  Sometimes they're using one of the older
ones, and repurposing lines like RTS.  The newer FTDI chips can be used
as a sort of parallel port interface.  A lot depends on the device
driver on the PC to set them up (and be aware, the random vendor on
Amazon may or may not be distributing drivers or sample code that
matches *their* particular implementation).

Jim Lux 2021/10/30 18:21

On 10/30/21 6:12 PM, Jim Lux wrote:
> On 10/30/21 5:56 PM, John Galbreath via groups.io wrote:
>> please show link to specification of this board.
>> looks like you are headed in right direction.
>> _._,_
>
>
> I've been fooling with USB relay boards recently, and there's
> *multiple* FTDI chips that get used.  Sometimes they're using one of
> the older ones, and repurposing lines like RTS.  The newer FTDI chips
> can be used as a sort of parallel port interface.  A lot depends on
> the device driver on the PC to set them up (and be aware, the random
> vendor on Amazon may or may not be distributing drivers or sample code
> that matches *their* particular implementation).

Found some notes. the FT-245R is different than the FT-232 series.  The
FT-245R requires a sequence to put it in "bit bang mode"

There are *other* USB relay boards that take a byte sequence to command
the relay on off. For instance, the SainSmart 8CH relay uses 0xff,
channel, 0x1 to turn the relay #channel on, and 0xff, channel, 0x0 to
turn it off.  You can send 0xff, 0x8+channel and get the relay state back.

Francesco 2021/10/31 05:16

Hello Jim, thank you for your generous offer to drive me on the ragth
direction.

This is the board on my possession, stand alone with is small software work
perfect, the pc reconize the driver, the the NanoVNA software reconoice the
usb board (tell me there is one error , LabWiu see de board is ok.

I read on the JS software manual:

**The software really doesn 't care what type of transfer relay is attached.
It uses a common USB - TTL adapter from FTDI. The RTS signal is used to select
the state of the relay and the CTS is used to monitor it's status. The
communications port is selected in the Setup/Diagnostics page using the
XferPort. Again, the BAUD rate has no effect. The selected port is saved as
part of the defaults. Shown is the FTDI cable attached to the Transco
controller.**

**19.1 Manually Controlling the Transfer Relay With the correct communications
port selected, the next time Link is selected, the software will check for the
presence of the port. There is no other check beyond it finding a valid port
number. If found the XferRly Lnk indicator (found on the main page), will
become active. You can manually change the state of the relay by selecting the
CH0-A switch on the front panel. Once selected, the Chan0-B indicator will
become active. If the relay does not change states, the XferRly Err indicator
will become active.**

Is possible from the NanoVNA software and the board some signal not floing?
**The RTS signal is used to select the state of the relay and the CTS is used
to monitor it 's status.**

**If I need to buy other relay bord is not problem.**

**Sorry Jim I 'm confused.**





**A general purpose USB Relay controller for connection to a PC 's USB port
using VCP (Virtual COM port). Control devices using your PC. USB Relay
controller allows a PC to control a single external device using simple RS232
commands. Relay is fully powered from the USB bus. Free test software.**

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Features:**
• Fully assembled and tested.
• Fully powered from USB
• For 12V/24V DC 15A or 120V/220V AC at 10A max.
• Can be used with LabVIEW, ProfiLab, DAQFactory, TestPoint, DASYLab, VEE
****

****![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ******Model:**
U1CR

****![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ******Complete
including:**
\- One USB One relay controller

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Dimensions** **
**(PCB board)** :**
90 mm / 35 mm

****![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ** Drivers:**
<http://www.ftdichip.com/Drivers/VCP.htm>

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Drivers are
available to work with the following operating systems:**
All Windows Systems, Linux, Mac OS X, Mac OS 9, Mac OS 8, Windows CE.NET
(Version 4.2 and greater)

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Communication
Parameters:**
8 Data, 1 Stop, No Parity
Baud rate : 9600

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Commands:**
OFF command: FF 01 00 (HEX) or 255 1 0 (DEC)
ON command: FF 01 01 (HEX) or 255 1 1 (DEC)

**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) ****Software:**
Download - [KMTronic_USB_Timer.zip](http://sigma-
shop.com/software/usb_relay/KMTronic_USB_Timer.zip)

**![](https://www.kmtronic.com/e_images/usb_timer_01.jpg)![](https://www.kmtronic.com/image/catalog/usb_timer_01.jpg)**


**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) More information:**
[info.KMtronic.com/USB-One-Channel-Relay-
PCB.html](http://info.kmtronic.com/usb-one-channel-relay-pcb.html)


**![](https://www.kmtronic.com/e_images/bullet_blue2.gif) Software
examples:**
[info.KMtronic.com/USB-RS232-RS485-Relays.html](http://info.kmtronic.com/usb-
rs232-rs485-relays.html)





**Sent:** Sunday, October 31, 2021 at 1:21 AM
**From:** "Jim Lux" <jim@luxfamily.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

On 10/30/21 6:12 PM, Jim Lux wrote:
> On 10/30/21 5:56 PM, John Galbreath via groups.io wrote:
>> please show link to specification of this board.
>> looks like you are headed in right direction.
>> _._,_
>
>
> I've been fooling with USB relay boards recently, and there's
> *multiple* FTDI chips that get used. Sometimes they're using one of
> the older ones, and repurposing lines like RTS. The newer FTDI chips
> can be used as a sort of parallel port interface. A lot depends on
> the device driver on the PC to set them up (and be aware, the random
> vendor on Amazon may or may not be distributing drivers or sample code
> that matches *their* particular implementation).

Found some notes. the FT-245R is different than the FT-232 series. The
FT-245R requires a sequence to put it in "bit bang mode"

There are *other* USB relay boards that take a byte sequence to command
the relay on off. For instance, the SainSmart 8CH relay uses 0xff,
channel, 0x1 to turn the relay #channel on, and 0xff, channel, 0x0 to
turn it off. You can send 0xff, 0x8+channel and get the relay state back.









_._,_._,_

* * *

Francesco 2021/10/31 05:21

This is the board photo.



![KMTRONIC SINGLE 1 CHANNEL USB RELAY BOARD COMPUTER PC CONTROLLER MODULE
REMOTE ](https://i.ebayimg.com/images/g/Jp8AAOSwadNdhKgH/s-l500.jpg)





**Sent:** Sunday, October 31, 2021 at 1:12 AM
**From:** "Jim Lux" <jim@luxfamily.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

On 10/30/21 5:56 PM, John Galbreath via groups.io wrote:
> please show link to specification of this board.
> looks like you are headed in right direction.
> _._,_


I've been fooling with USB relay boards recently, and there's *multiple*
FTDI chips that get used. Sometimes they're using one of the older
ones, and repurposing lines like RTS. The newer FTDI chips can be used
as a sort of parallel port interface. A lot depends on the device
driver on the PC to set them up (and be aware, the random vendor on
Amazon may or may not be distributing drivers or sample code that
matches *their* particular implementation).








_._,_._,_

* * *

Francesco 2021/10/31 05:23

Thank you John.





**https://www.kmtronic.com/usb-relays.html/usb-relay-controller-one-channel-
pcb.html**



**Sent:** Sunday, October 31, 2021 at 12:56 AM
**From:** "John Galbreath via groups.io" <nc0gnit0=yahoo.com@groups.io>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

please show link to specification of this board.
looks like you are headed in right direction.

_._,_._,_

* * *

Jim Lux 2021/10/30 21:33

On 10/30/21 9:16 PM, Francesco wrote:
>
> Hello Jim, thank you for your generous offer to drive me on the ragth
> direction.
>
> This is the board on my possession, stand alone with is small software
> work perfect, the pc reconize the driver, the the NanoVNA software
> reconoice the usb board (tell me there is one error , LabWiu see de
> board is ok.
>
> I read on the JS software manual:
>
> *The software really doesn’t care what type of transfer relay is
> attached. It uses a common USB – TTL adapter from FTDI. The RTS signal
> is used to select the state of the relay and the CTS is used to
> monitor it’s status. The communications port is selected in the
> Setup/Diagnostics page using the XferPort. Again, the BAUD rate has no
> effect. The selected port is saved as part of the defaults. Shown is
> the FTDI cable attached to the Transco controller.*
>
> *19.1 Manually Controlling the Transfer Relay With the correct
> communications port selected, the next time Link is selected, the
> software will check for the presence of the port. There is no other
> check beyond it finding a valid port number. If found the XferRly Lnk
> indicator (found on the main page), will become active. You can
> manually change the state of the relay by selecting the CH0-A switch
> on the front panel. Once selected, the Chan0-B indicator will become
> active. If the relay does not change states, the XferRly Err indicator
> will become active.*
>
> Is possible from the NanoVNA software and the board some signal not
> floing?*The RTS signal is used to select the state of the relay and
> the CTS is used to monitor it’s status.*
>
> *If I need to buy other relay bord is not problem.*
>
> *Sorry Jim I'm confused.*
>

You found it.. your relay board is using the NEW FTDI chip (the FT245R)
which is designed for discrete relay controlling (typically as a 1,2, 4,
8 channel application).

Joe's software is assuming it's a serial port (which it is not) and
using RTS/CTS serial lines. Typically a FT232 or similar chip.

Both look like a serial port to the operating system, but for one, you
control the "modem control" lines, the other, you send a byte string to
the unit.


So here's the question, which Joe can hopefully answer: Is the software
asserting RTS to put the transfer switch in one position, and
deasserting RTS to put the transfer switch in the other position?  If
so, then is your transfer switch a single control line or is it two (as
a latching relay)?








Francesco 2021/10/31 05:41

This is the caracteristic of the relay on the board, on the attacced file.







![Image 1 - KMTRONIC SINGLE 1 CHANNEL USB RELAY BOARD COMPUTER PC CONTROLLER
MODULE REMOTE ](https://i.ebayimg.com/images/g/Jp8AAOSwadNdhKgH/s-l1600.jpg)



**Sent:** Sunday, October 31, 2021 at 4:33 AM
**From:** "Jim Lux" <jim@luxfamily.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

On 10/30/21 9:16 PM, Francesco wrote:
>
> Hello Jim, thank you for your generous offer to drive me on the ragth
> direction.
>
> This is the board on my possession, stand alone with is small software
> work perfect, the pc reconize the driver, the the NanoVNA software
> reconoice the usb board (tell me there is one error , LabWiu see de
> board is ok.
>
> I read on the JS software manual:
>
> *The software really doesn't care what type of transfer relay is
> attached. It uses a common USB - TTL adapter from FTDI. The RTS signal
> is used to select the state of the relay and the CTS is used to
> monitor it's status. The communications port is selected in the
> Setup/Diagnostics page using the XferPort. Again, the BAUD rate has no
> effect. The selected port is saved as part of the defaults. Shown is
> the FTDI cable attached to the Transco controller.*
>
> *19.1 Manually Controlling the Transfer Relay With the correct
> communications port selected, the next time Link is selected, the
> software will check for the presence of the port. There is no other
> check beyond it finding a valid port number. If found the XferRly Lnk
> indicator (found on the main page), will become active. You can
> manually change the state of the relay by selecting the CH0-A switch
> on the front panel. Once selected, the Chan0-B indicator will become
> active. If the relay does not change states, the XferRly Err indicator
> will become active.*
>
> Is possible from the NanoVNA software and the board some signal not
> floing?*The RTS signal is used to select the state of the relay and
> the CTS is used to monitor it's status.*
>
> *If I need to buy other relay bord is not problem.*
>
> *Sorry Jim I'm confused.*
>

You found it.. your relay board is using the NEW FTDI chip (the FT245R)
which is designed for discrete relay controlling (typically as a 1,2, 4,
8 channel application).

Joe's software is assuming it's a serial port (which it is not) and
using RTS/CTS serial lines. Typically a FT232 or similar chip.

Both look like a serial port to the operating system, but for one, you
control the "modem control" lines, the other, you send a byte string to
the unit.


So here's the question, which Joe can hopefully answer: Is the software
asserting RTS to put the transfer switch in one position, and
deasserting RTS to put the transfer switch in the other position? If
so, then is your transfer switch a single control line or is it two (as
a latching relay)?









>
> ***Drivers are available to work with the following operating systems:*
> All Windows Systems, Linux, Mac OS X, Mac OS 9, Mac OS 8, Windows
> CE.NET (Version 4.2 and greater)
>
> ***Communication Parameters:*
> 8 Data, 1 Stop, No Parity
> Baud rate : 9600
>
> ***Commands:*
> OFF command: FF 01 00 (HEX) or 255 1 0 (DEC)
> ON command: FF 01 01 (HEX) or 255 1 1 (DEC)
>
> ****
>







_._,_._,_

* * *

Francesco 2021/10/31 05:50

If there is other relay board more suitable for drive the RF trasfere relay is
ok for me.

**The RF relay on the HP 8711A KO2 SWICHING TEST SET hare two 15 volt lach
relays.**





**Sent:** Sunday, October 31, 2021 at 4:33 AM
**From:** "Jim Lux" <jim@luxfamily.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

On 10/30/21 9:16 PM, Francesco wrote:
>
> Hello Jim, thank you for your generous offer to drive me on the ragth
> direction.
>
> This is the board on my possession, stand alone with is small software
> work perfect, the pc reconize the driver, the the NanoVNA software
> reconoice the usb board (tell me there is one error , LabWiu see de
> board is ok.
>
> I read on the JS software manual:
>
> *The software really doesn't care what type of transfer relay is
> attached. It uses a common USB - TTL adapter from FTDI. The RTS signal
> is used to select the state of the relay and the CTS is used to
> monitor it's status. The communications port is selected in the
> Setup/Diagnostics page using the XferPort. Again, the BAUD rate has no
> effect. The selected port is saved as part of the defaults. Shown is
> the FTDI cable attached to the Transco controller.*
>
> *19.1 Manually Controlling the Transfer Relay With the correct
> communications port selected, the next time Link is selected, the
> software will check for the presence of the port. There is no other
> check beyond it finding a valid port number. If found the XferRly Lnk
> indicator (found on the main page), will become active. You can
> manually change the state of the relay by selecting the CH0-A switch
> on the front panel. Once selected, the Chan0-B indicator will become
> active. If the relay does not change states, the XferRly Err indicator
> will become active.*
>
> Is possible from the NanoVNA software and the board some signal not
> floing?*The RTS signal is used to select the state of the relay and
> the CTS is used to monitor it's status.*
>
> *If I need to buy other relay bord is not problem.*
>
> *Sorry Jim I'm confused.*
>

You found it.. your relay board is using the NEW FTDI chip (the FT245R)
which is designed for discrete relay controlling (typically as a 1,2, 4,
8 channel application).

Joe's software is assuming it's a serial port (which it is not) and
using RTS/CTS serial lines. Typically a FT232 or similar chip.

Both look like a serial port to the operating system, but for one, you
control the "modem control" lines, the other, you send a byte string to
the unit.


So here's the question, which Joe can hopefully answer: Is the software
asserting RTS to put the transfer switch in one position, and
deasserting RTS to put the transfer switch in the other position? If
so, then is your transfer switch a single control line or is it two (as
a latching relay)?









>
> ***Drivers are available to work with the following operating systems:*
> All Windows Systems, Linux, Mac OS X, Mac OS 9, Mac OS 8, Windows
> CE.NET (Version 4.2 and greater)
>
> ***Communication Parameters:*
> 8 Data, 1 Stop, No Parity
> Baud rate : 9600
>
> ***Commands:*
> OFF command: FF 01 00 (HEX) or 255 1 0 (DEC)
> ON command: FF 01 01 (HEX) or 255 1 1 (DEC)
>
> ****
>







_._,_._,_

* * *

Joe Smith 2021/10/31 11:43

On Sun, Oct 31, 2021 at 12:33 PM, Jim Lux wrote:

>
> Joe's software is assuming it's a serial port (which it is not) and using
> RTS/CTS serial lines. Typically a FT232 or similar chip.
>
> ...
>
> So here's the question, which Joe can hopefully answer: Is the software
> asserting RTS to put the transfer switch in one position, and deasserting
> RTS to put the transfer switch in the other position?  If so, then is your
> transfer switch a single control line or is it two (as a latching relay)?

>From the manual:

*"It uses a common USB – TTL adapter from FTDI.   The RTS signal is used to select the state of the relay and the CTS is used to monitor it’s status."*

*"The transfer relay is controlled by the state of the RTS pin.  When RTS is de-asserted, Port 1 and 2 of the VNA will route to Ports 1  and 2 of the transfer relay.  When RTS is asserted, Port 1 and 2 of the VNA will route to Ports 2  and 1 of the transfer relay.   The software expects the transfer relay to always assert the CTS pin,  or it will set the transfer relay error (XferRly Err)."*

*"The Transco relay requires 24V and is a latching type relay.  A simple DC-DC converter was designed using a 7400 gate that boosts the USB voltage to 24V and charges a large capacitor.  This capacitor holds the charge needed to drive the relay.*

*Figure 93 shows the DC-DC converter made from a 7404 hex inverter.  The two remaining gates are used to buffer the signals to drive the relay coils.   This is not meant as a reference to base your own design from.  Rather this is what I put together with what I had on hand."*

Jim Lux 2021/10/31 12:10

OK.. looking at the latest rev of the manual starting at page 109:  Fig 93 shows the DC/DC converter, but doesn't show anything on you you turn a single RTS line into two pulsed  lines for the latching transfer switch. I assume that's the "two remaining gates"

Maybe a figure with the actual RTS -> coils would help?  I can think of some ways to do it (series capacitor, diodes, etc. to turn an edge into a pulse), but if you've already done it, it would help.

Then, back to Francesco's challenge..

Francesco - I think the HP unit you are using has two SPDT relays which may or may not be latching (I can't remember from when I looked at the schematics a few weeks ago) - There might also be some drive electronics that turns a level (the RTS from the serial port) to pulsed signals (if latched).

Ultimately, though, to be compatible with Joe's software, you need a regular old USB serial port, as opposed to a USB relay.

Francesco 2021/10/31 21:09

Yes the HP unity have one board to drive the relay I scrap out, on this moment
the HP unity work perfect with one manual temporary ON-OFF-ON switch toggle,
the relay hare 15Volt Latch relay I drive them with 15 volt PSU. (on the
attached file is my unfinished Nano VNA trasfere relay box)

My big problem is software Hardware is my work no problem on the moment I get
to work one USB relay board give me one NC and NO is end of the story.



If there is some genius HP expert to drive the serial original board EUREKA!!
the original board of the HP 8711A KO2 SWITCHING TEST SET receive some command
from the HP VNA.



I think if is possible to drive one small relay with one of this board: **USB
to RS485 TTL Serial Converter Adapter FTDI interface FT232RL 75176 Module.**
https://i.ebayimg.com/images/g/jdcAAOSwXY5ZVMa0/s-l1600.jpg

**Please tell me if one of this maybe work?**

**Thank you for all help and suggestions realy appreciate.**

**Francesco.**

**Features:**

Standard: USB2.0 standard, backward compatible, in line with the standard
RS485
Direction control: the use of automatic data flow control, auto distinguish
and control data transfer direction
Baud :300-9216000bps, automatically detecting the serial signal data rate
Load capacity: support multipoint, each converter allows RS485 interface
device to connect 32
Interface Protection: TVS tube protection, USB self-recovery protection
Support Windows98/ME/2000/XP/WIN7/Vista, Linux, Mac
Support devices with RS485 interface: surveillance cameras, video capture
device, fingerprint attendance machine, PBX, CNC machine, microcontroller,
etc.

This converter provides two way serial communications signal
conversion between the RS485
to and from a personal computer USB port
using virtual serial COM port.
Self-powered from USB
FT232RL+75176
you can have up to 32 devices on the bus





![Image 1 - USB to RS485 TTL Serial Converter Adapter FTDI interface FT232RL
75176 Module Ne](https://i.ebayimg.com/images/g/jdcAAOSwXY5ZVMa0/s-l1600.jpg)



**Sent:** Sunday, October 31, 2021 at 7:10 PM
**From:** "Jim Lux" <jim@luxfamily.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

OK.. looking at the latest rev of the manual starting at page 109: Fig 93
shows the DC/DC converter, but doesn't show anything on you you turn a single
RTS line into two pulsed lines for the latching transfer switch. I assume
that's the "two remaining gates"

Maybe a figure with the actual RTS -> coils would help? I can think of some
ways to do it (series capacitor, diodes, etc. to turn an edge into a pulse),
but if you've already done it, it would help.

Then, back to Francesco's challenge..

Francesco - I think the HP unit you are using has two SPDT relays which may or
may not be latching (I can't remember from when I looked at the schematics a
few weeks ago) - There might also be some drive electronics that turns a level
(the RTS from the serial port) to pulsed signals (if latched).

Ultimately, though, to be compatible with Joe's software, you need a regular
old USB serial port, as opposed to a USB relay.

_._,_._,_

* * *

Joe Smith 2021/10/31 13:55

On Mon, Nov 1, 2021 at 03:10 AM, Jim Lux wrote:

>
>
>
> OK.. looking at the latest rev of the manual starting at page 109:  Fig 93
> shows the DC/DC converter, but doesn't show anything on you you turn a
> single RTS line into two pulsed  lines for the latching transfer switch. I
> assume that's the "two remaining gates"
>
>
>
> Maybe a figure with the actual RTS -> coils would help?  I can think of
> some ways to do it (series capacitor, diodes, etc. to turn an edge into a
> pulse), but if you've already done it, it would help.
>
>

I had constructed a couple of low cost transfer relays.  One solid-state (similar to the datasheet I provided), the other mechanical.  All three of these require different drives.  I did not include the hardware details as I assume the EE will design their own driver.   Rather I just include the functional requirements so they can design around that.

Turn key solutions would be the V3 if OWOs company ever moves forward with it.  Another possibility is Jankae's.  Both under $600 USD.  My plan is to procure the V3 if it ever becomes available and port my software over to it.

As for controlling the vintage Transco relay I show,  I buffer the RTS pin with one gate.  I use the last gate to invert the signal, forming a differential pair.  These two gates are then RC coupled into the base of two small signal transistors.  Most likely I used a 2n2222, 4401 or 3906.  Not important.   The relay's coils are fairly low resistance but because it is latching, it comes down to the pulse time required.  I think I targeted 100ms.  This is set by the two RC networks.  I wanted to run it from the USB port's power, so I made up a simple DC-DC converter that charges a large capacitor that I dump across the coils when one of the transistors turns on.     Making the one-shots could be done any number of ways.  I just went quick and dirty.   A few minutes with the soldering iron, a bit of SPICE work and some quick measurements of the Transco relay.

Francesco 2021/11/01 07:38

Hello, last night I started to figure the set-up on the NanoVNA software for the transfer relay, *Yes I get one signal on the RTS to pin 7* on one USB to serial cable switching ON OFF from the software, I waiting to get one USB to TTL interface and hope to find the way if get some suggestions. My problem is I don't have experience with digital stuff I buy the board assembled for my limitations.

Francesco 2021/11/04 14:07

I searching on the Webb one diagram to drive the transfer relay from the RTS pin.

Guido ON7CH 2021/11/04 22:43

Hi Francesco,

I also need to build an s-parameter test set.
Hereby the parts and the principle scheme that I am looking to use. See
attachments.
I will keep you informed of the further construction results.

guido on7ch

On Thu, Nov 4, 2021 at 10:07 PM Francesco <realfran@gmx.co.uk> wrote:

Francesco 2021/11/05 11:57

Hello Guido, thank you for the diagram, my set up is 2 transfer latch relays
of 15 volt ad moment I use one temporaney toggle switch ON-OFF-ON to change
the state of relay, one small latch relay to drive one 2 color LED to tell me
the position of the NanVNA ports I put every think on the inside the box ( I
don't like move around on my small desk and fall on the
floor![](https://s.uicdn.com/3c-cdn/mail/client/wicket/resource/static-
res/---/mc/img/smileys/default/s_01.gif) )



The transistor on my possession hare BC 546B, my difficulty is drive from the
RTS pin ready made relay boards I got some difficulty for soldering (shacking
hands)



73/Francesco

G7OYO





**Sent:** Thursday, November 04, 2021 at 9:43 PM
**From:** "Guido ON7CH" <g.charita@gmail.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

Hi Francesco,



I also need to build an s-parameter test set.
Hereby the parts and the principle scheme that I am looking to use. See
attachments.
I will keep you informed of the further construction results.



guido on7ch



On Thu, Nov 4, 2021 at 10:07 PM Francesco
<[realfran@gmx.co.uk](mailto:realfran@gmx.co.uk)> wrote:

> I searching on the Webb one diagram to drive the transfer relay from the RTS
pin.

>

>
>

>

_._,_._,_

* * *

Francesco 2021/11/05 21:06

Hello Guido, I forgot to tell you I'm really grateful if yo like help me on
this, (tray to get the cable short and the same size for the switching relay)

73/Francesco.

G7OYO





**Sent:** Friday, November 05, 2021 at 10:57 AM
**From:** "Francesco" <realfran@gmx.co.uk>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

Hello Guido, thank you for the diagram, my set up is 2 transfer latch relays
of 15 volt ad moment I use one temporaney toggle switch ON-OFF-ON to change
the state of relay, one small latch relay to drive one 2 color LED to tell me
the position of the NanVNA ports I put every think on the inside the box ( I
don't like move around on my small desk and fall on the
floor![](https://s.uicdn.com/3c-cdn/mail/client/wicket/resource/static-
res/---/mc/img/smileys/default/s_01.gif) )



The transistor on my possession hare BC 546B, my difficulty is drive from the
RTS pin ready made relay boards I got some difficulty for soldering (shacking
hands)



73/Francesco

G7OYO





**Sent:** Thursday, November 04, 2021 at 9:43 PM
**From:** "Guido ON7CH" <g.charita@gmail.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

Hi Francesco,



I also need to build an s-parameter test set.
Hereby the parts and the principle scheme that I am looking to use. See
attachments.
I will keep you informed of the further construction results.



guido on7ch



On Thu, Nov 4, 2021 at 10:07 PM Francesco
<[realfran@gmx.co.uk](mailto:realfran@gmx.co.uk)> wrote:

> I searching on the Webb one diagram to drive the transfer relay from the RTS
pin.

>

>
>

>

_._,_._,_

* * *

Francesco 2021/11/09 23:39

Hello Guido, for my lach relay is 12volt I need change some value?

Best regards.

Francesco





**Sent:** Thursday, November 04, 2021 at 9:43 PM
**From:** "Guido ON7CH" <g.charita@gmail.com>
**To:** NanoVNAV2@groups.io
**Subject:** Re: [nanovnav2] Please some help to integrate trasfere relay

Hi Francesco,



I also need to build an s-parameter test set.
Hereby the parts and the principle scheme that I am looking to use. See
attachments.
I will keep you informed of the further construction results.



guido on7ch



On Thu, Nov 4, 2021 at 10:07 PM Francesco
<[realfran@gmx.co.uk](mailto:realfran@gmx.co.uk)> wrote:

> I searching on the Webb one diagram to drive the transfer relay from the RTS
pin.

>

>
>

>

_._,_._,_

* * *

Guido ON7CH 2021/11/11 13:39

Francesco,
In the attachment the info how I built my s-parameter test set.
guido


On Tue, Nov 9, 2021 at 11:39 PM Francesco <realfran@gmx.co.uk> wrote:

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