Model S4000CH
49
6.8.23 HazardWatch (Co – Calibration Output) (19h)
HazardWatch indicates when a successful calibration takes place. In HazardWatch mode
the current goes to 3.2 mA for 5 seconds then to 4.0 mA. An aborted calibration would go
straight to 4.0 mA. A read to this register will return the status of the HazardWatch option.
0x01 enables this option, 0x00 disables this option, similar to the write.
NOTE:
When HART is in use, the current does not go to 3.2 mA but stays at 3.5 mA.
6.8.24 ARGC (1Ah)
The Automatic Remote Gas Calibrator is enabled or disabled by this command. A “1”
enables the ARGC option and a “0” disables the option.
NOTE:
When the ARGC is enabled the remote calibration input does not function.
6.8.25 PLC Remote Gas Calibration
The Enable Sol and Sol ON/OFF functions work together. Their use is to allow a PLC to
turn on and off gas during a calibration or gas check. The PLC would look at the MODE
register and activate or deactivate a calibration gas control valve.
6.8.25.1 Enable Sol (1Bh)
This function is a built-in safety feature. The solenoid must be enabled first before it can
be activated. This disables the remote cal function and enables the solenoid.
A “0” enables the remote calibration (Normal) and disables the solenoid. A “1”
disables the remote calibration and enables the solenoid.
6.8.25.2 Sol ON/OFF (1Ch)
To use this function, it must first be enabled by the Enable Sol function.
Solenoid on 10
Solenoid off 20
Return to normal 30
If the read command returns a 30, then the Sol ON/OFF function is not enabled.
NOTE:
If the ARGC is enabled, the solenoid cannot be used and an exception will be
returned.
6.8.26 HART Enable (1Dh)
This command enables or disables the HART. A “0” is Modbus and a “1” is HART.
6.8.27 HART Test (1Eh)
This command is used to test the HART output. It produces constant zeros or constant ones
on the HART output.