Click PLC Serial Send Help

As pointed out in a welcome PM I was referring to the serial port on the servo being TTL not the serial port on the Click. Sorry for any confusion.

Bernie,

I am using a modified interface cable (serial cable with level shifting IC installed in the DB9) that came with a previous DMM servo drive. I spliced this to a RJ12 connector from the Click. Pins 1 and 4 from port 2 are connected to the DMM drive JP2 pins 1 and 5, respectively, through the level shifter.

I didn't have much time tonight to work with it, but maybe I'll have better luck tomorrow.

Thanks again.

OK then. So much for that guess.

Does the Click need Receive connected for handshaking?

Getting back to the termination characters, you have tried the Carriage Return code, 0x0D, but have you tried the Line Feed code, 0x0A as well?
Your screenshot shows sending the individual bytes with a carriage return, but not with a line feed, and you indicated that this worked when you had the sent bytes in a column on your serial monitor.

Looking at your screen caps from your initial testing and my rudimentary understanding of the C++ program in the documentation, it appears the included software ensures there is no data in the buffer before sending the next command. It also appears to read prior to each write. Perhaps add a read prior to each byte. No need to do anything with the data from the read. This should also break up your transmission to multiple lines as the test software does.

I finally had a chance to try the last couple of suggestions but still have not had any luck. Most recently, I added receive commands before sending each byte but the drive still did not respond. I did this with and without time delays.

I connected the Click back into my serial monitoring software and the four bytes still show up on one line. I have no idea if the multiple lines is necessary, but I just can't get over the differences between the Click's output and the drive's test software outputs.

For now, to keep the project moving, I may just switch to an a Micro830 PLC and use the PTO to control the drive with step/direction. I was really hoping the Click would work, and still may experiment some more. Any other ideas? I'm about out of them. I appreciate everyone's help and suggestions!

The command needs to be on one line. All four bytes need to be sent "jammed together". Your monitor software shows a space between each byte. Is it adding that, or are spaces coming from the Click?
Needs to be [ 7F8ABCC5 ], not [ 7F208A20BC20C520 ].

Any way to see the true Hex being sent? Can you give a screenshot of the command box from the Click software?

Are you using the same TTL cable for the PC as you are using for the Click? Is there a way in the Click to force RTS / CTS on? I imagine a converter like that requires power from the host to operate. I have inline 232 to 422/485 converters that require power vis RTS pin. The included software may be forcing one of those pins high without your knowledge. I'm guessing that the Click isn't powering the converter.