What causes the open circuit failure of the Honeywell module?

The open circuit failure of the Honeywell module may be caused by the following reasons.

1. ‌Wiring error or line failure‌

Check whether the wiring of the keyboard or module is correct, and confirm the line sequence according to the manual (such as the host terminal 6/7/8/9 corresponds to the keyboard line color red/black/green/yellow). If the bus is short-circuited or the load is too large, it is necessary to check each node branch in sections to eliminate the short-circuit point.

2. ‌Monitoring resistor abnormality‌

If the monitoring resistor of the Honeywell module is not connected correctly or damaged, it will cause an open circuit alarm. It is necessary to check whether the resistor is installed normally or replace it.

3. ‌Power supply voltage problem‌

Measure the host terminal voltage: 1/2 terminals should be AC 16.5V, and 6/7 terminals should be DC 12V. If abnormal, it may be due to damage to the transformer or power supply and needs to be replaced. When the backup battery voltage of the Honeywell module is insufficient (such as "SYSTEM LOBAT" is displayed), it is necessary to charge or replace the battery.

4. ‌Module or detector failure‌

If the open circuit is still reported after replacing the module, check whether the zone detector is damaged or the signal line is broken. If it is a HONEYWELL 05704-A-0144 regulator module, confirm whether its bridge balance and signal gain settings are normal.

5. ‌Programming or communication setting error‌

When the host address code is not programmed correctly, re-enter the address code (such as pressing "1" and "3" keys at the same time to set 01). Communication failure requires checking the serial port settings (such as programming items 170-173) or replacing the communication module.

‌Recommended operation process‌, first check the wiring and power supply, then check the resistance and module status, and finally verify the programming settings. If the problem persists, contact professional maintenance service.