No COMM From Micro to STP1
system
Description
No COMM From Micro to STP1 means 1-1MSM cannot communicate with 1-2MSM over the CAN bus; shut down and alarm.
Activation Conditions
1-1MSM cannot communicate with 1-2MSM over the CAN bus.
Unit Behavior
Shut down and alarm. The stepper valve module status LED may be on steady green (not pulsing) or red. RESET CONDITION: Auto reset when CAN communication is restored, alarm reset or alarm may be manually reset by turning the unit off, then back on again. NOTE Follow the steps below until a problem is found. Once a repair or correction has been made, clear the alarm(s). (Refer to Note 1 in Section 7.2) Operate the unit through the appropriate modes to see if any active alarm occurs. Continue with the steps below as necessary.
Reset Conditions
See manual.
Corrective Actions
1. Check Both Active and Inactive Alarms for other “NO COMM” Alarms a. If more than one alarm, record all and proceed to step 2. b. If this is the only “NO COMM” alarm, replace module. 2. Check CAN Bus a. Inspect connector pins and terminals on 1-1MSM and 1-2MSM. Verify that there is no damage or corrosion in connections. b. Check CAN circuits: CAN Hi: 1-1MSM-12 and 2, 1-2MSM-29 CAN Lo: 1-1MSM-3 and 6, 1-2MSM-30 LGC Power (+ 12 VDC): 1-1MSM-10 LGC GND: 1-1MSM-1 3. Check System: Clear active and inactive alarms. Start unit and monitor for additional “NO COMM” alarms.