I have an old CAEN Sy127 high voltage supply which I would like to control from a modern linux machine. The Manual (p. 20; also there is a more thorough documentation of the communications module in section 2.3 starting on p.9) says that the HV system can be controlled by any VT52-compatible terminal. I have the system connected to the linux PC using a cable with 25-pin RS232 on one end and 9-pin RS232 on the other, going into a Digitus RS232 to USB adapter.
I believe I can emulate a VT52 terminal using xterm -ti vt52 -tn vt52 and then connect the terminal to the device using kermit, but to be honest I do not really know what I am doing (this is my first time using kermit). In kermit I set the baud rate, parity and stop bits according to what is set in the CAEN system. When I try to connect it says carrier required but not detected. with set carrier-watch off it seems to connect but I don't get any response from the device and can't input any characters.
What could be the issue here? Is there maybe something simple that I am missing, since I don't have much experience in this area?
Also please let me know in case there is a better way than using xterm and kermit. I have found people using screen for similar things but it doesn't seem to be working either and I'm not sure if it can emulate VT52.
I originally posted this on the electrical engineering stack exchange but was directed here since my questions are mainly on the software side.
Edit: I tried using minicom and picocom and neither worked. I took another look at the manual and about the DSR port it says "Ignored if not connected. If connected, must be asserted externally for Data Transmission to proceed" (p. 17) and that xon/xoff is also supported. I tried setting the flow control to xon/xoff in picocom but still got nothing.
The cable I am using has male DB-25 on one end (going into the voltage supply) and female DB-9 on the other. The USB Adapter has male DB-9.
I tested the connections of the cable and on the DB-9 end only pins 2, 3 and 5 are connected, so no DSR. Pin 2 of the DB-9 connector is connected to pin 3 of the DB-25 and vice versa, which should be correct according to my understanding. Pin 5 is ground.
