We build control for show control with PLCs and we love using the WAV trigger for sounds. Normally we just use contact closure from the PLC to trigger sounds. However larger jobs that need several sounds are getting messy with all the wires so we would like to start using Serial Control.
When I hook up a FTDI USB to the WAV Trigger the WAV Trigger serial Control seems to work great.
https://www.amazon.com/Adapter-Serial-C … B075N82CDL
Then I hooked it up to a USB to RS232 adapter and RS232 to TTL converter but I got no response. Checking the signal on an oscilloscope I see the converter is reducing the voltage but not inverting the signal. The converter I am using has a MAX3232 chip in it.
https://www.amazon.com/Anmbest-Converte … 82&sr=1-26
I am not sure what I am missing, does the MAX3232 invert the signal? If not, is there a converter that does? Is there a better way to make this work?
What specific products are you using for the USB-to-RS232 and RS232-to-TTL converters?
Given that you’ve tried multiple sources of RS232 and only one RS232-to-TTL converter, and the output of that looks wrong, I would tend to point the finger at the converter. Why go to RS232 signal level in the first place? Is it because you need to use the PLC outputs?
I did buy a pack of five of those RS232>TTL convertors. I tried a few of them. I have a different brand of converter coming tomorrow that uses the MAX 232 chip but it is a crap shot. Just having trouble finding the correct product. Was hoping to find out what others are using to control the WAV trigger when faced with “real” RS232.
Correct, the PLC only have RS232 or RS485 output. In the future we are hoping to use a P1AM PLC which is Arduino based but it has been difficult talking customer into it when they expect “industrial” type equipment.
https://www.automationdirect.com/adc/sh … s/p1am-100
Just for confirmation, are you using a pass through cable, not a null modem cable, to connect the USB-RS232 adapter to the RS232-TTL converter?
There is no real RS232 cable. Just a cable with the USB>Serial RS232 adaptor, that DB9 plugs right into the converter RS232>TTL board. From that board is single conductors and I have been swapping RX and TX when testing. But yes, thanks for the heads up.
Update. Tried a different converter board (link in previous post) and it works now. Also the new board runs on 5v so I only have to use one power supply as opposed to an additional 3.3v supply.
Also for those who are interested, the BRX PLC worked as it can send HEX strings, the Click brand PLCs I have not gotten to work because all it will send out is ASCII.
Hmm, did I miss something? All of the boards you link above have male DB9 connectors, so I don’t follow how you have the USB-RS232 and RS232-TTL boards connected without a cable, or a gender changer at least. Anyway, it looks like you’ve made progress, so this is probably a moot discussion. Glad you got it working!
I ordered the newer converter with female DB9’s. Weird how only one worked when they both had MAX3232 chips? Order packs of five so I tried several. Anyway cool boards now onto programming…
Thanks
