AERCO BMS II BOILER - Manual (Page 64)

TROUBLESHOOTING
5-2
Table 5-1. Fault Messages – Continued
Fault Message Description & Possible cause
CURRENT LOOP
ERROR
The 4-to-20-mA remote input signal has dropped below 3 mA, or the signal is
not present at the BMS II.
FAIL SAFE MODE
ACTIVATED
This message indicates that the BMS II is operating in the Fail Safe (Constant
Setpoint) mode.due to sensor loss or signal loss.
MODBUS TIMEOUT
ERROR Displayed during Modbus Remote Setpoint operation when the BMS II is
functioning as a Slave to an EMS Master. Error indicates that the Network
Timeout has expired.
NETWORK DISABLED
MODBUS LISTEN
Displayed during Modbus operation when the “FORCE LISTEN ONLY”
Modbus diagnostic command is sent to the BMS II Slave by the controlling
Master, thereby disabling normal Modbus Network communication. It
indicates that the BMS II is listening for the “RESTART COMMUNICATIONS
OPTIONS” diagnostic command required to restart normal Modbus
communication. The BMS II will operate in the Fail Safe mode during this
period.