Baud rate

[buffalonymann]

I have a CNC router that employs a WIN7 PC to run the router software connected to a Compact 984-145 controller via modbus and an ethernet connection to a Galil motion controller. I seem to be getting stop codes to my motion controller mid-cycle of a router cut. I think these are watchdog time outs. My thought is to use the 19200 baud rate between PC and Modicon 984 rather than the 9600....any thoughts?

 

[Steve Bailey]

Serial communications timeouts are rarely cured by speeding up the baud rate, particularly if they used to work well and suddenly started showing problems. A more likely cause is electrical interference on the serial cable. Has anything that might generate noise been installed recently? Check to make sure that the cable shield is properly grounded. It should be grounded at one end only, preferably at the end closest to the greatest potential source of noise.

 

[buffalonymann]

Well, I don't know if this is new or not. They've had trouble with this machine for more than (1) year. In addition to the stop codes, I was getting faults on my motion controller, I tracked that problem to a bad comm port on the 984-145 controller. The cable between controller and pc is 9 ft long but the distance is only 3 ft, so its coiled and not near any sorce of interference. I'm going to make a new cable, but I need to get the pin out config from the router manufacturer to eliminate a crossed wire possibility. I did notice when I connect my laptop, comms slows down quite a bit