I’ve got an AB7318 connected to a 1769-L33ER PLC and no matter which method I try (cyclic or trigger byte) I cannot get anything onto the bus, judging by the line listener. I always have a “passive error”, no matter what I do. I have checked that my instance sizes line up; I have green lights on LEDs 1 & 2. LED 6 is also solid, and LED 5 is flashing green.
I’ve checked that my mapping between the PLC and AB lines up, I’ve been able to trigger reboots using the control word, but when I change the value of the trigger byte I get nothing on the line listener.
In trying to narrow the problem down, I unplugged the CAN connector from the Anybus, am I right to assume that I should still see frames from my Produce transaction?
Could it be my terminating resistor? Between current and past projects the electrical drawings indicate 120ohm resistor on the end of the bus cable, on the end and at the beginning of the bus cable, or no resistor at all. Could this be my problem?
Any ideas on what could be wrong, or tests I can do to prove out if I’m doing something wrong or if there’s something wrong with the module? I’ve included my PLC program and configuration for review as well.