Sensor/Transmitter Communication Failure; Boot-Up Phase After Turn-On - AMC SIR Series Instruction Manual

AMC-SIR Refrigerant Gas Sensor/Transmitter
Caution:
Maximum load resistance is 500 ohms @ 24VDC, 300 ohms @ 14VDC. Special
consideration is required to provide the transmitter with enough supply voltage as
lowering the supply voltage reduces the maximum load allowable. See section 4.3 for
appropriate cable lengths to accommodate required supply voltages.

4.2.1.4 SENSOR/TRANSMITTER COMMUNICATION FAILURE

If the sensor malfunctions, this state is indicated as follows at the current output:

4-20mA operation → output current is frozen at 3.5mA.
Depending on the operating mode and the downstream evaluation, such a state can then be
used for fault detection purposes. When the defect is fixed, the AMC-SIR Refrigerant Gas
sensor/transmitter automatically begins its normal boot-up phase and then switches back to
normal mode, as described in section 4.2.1.5.

4.2.1.5 BOOT-UP PHASE AFTER TURN-ON

After the power supply and the desired interface have been connected to the AMC-SIR
Refrigerant Gas sensor/transmitter, the sensor starts with a boot phase. This lasts less than 2
minutes and serves to check all internal components and routines. During the boot phase, the
following states can occur depending on the selected operating mode:

4-20mA output:
When the boot phase is finished, and when all test routines have properly finished, the AMC-
SIR Refrigerant Gas sensor/transmitter automatically switches to normal operating mode and
provides a signal output proportional to the gas concentration.
Caution:
The AMC-SIR Refrigerant Gas sensor/transmitter must be in operation for 60 minutes
to achieve full stabilization.
Initial output current is approx. 3.2mA, increasing to 4mA after about
2 minutes, in a gas-free environment.
The sensor signal can fluctuate during the warm-up period.
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