Hart Current Range (2E); Input Voltage (33H); Dip Switch Settings (36H); User Information (68H To 77H) - MSA FL500 Operating Manual

3.26. HART Current Range (2E)

Usually in HART mode, the low current does not go below 3.5 mA. A special HART setting lets the current go
as low as 1.25 mA so the difference between a COPM Fault and a Fault can be identified.
A Read command sends back 0 to identify 3.5 to 20 mA current, or 1 to identify 1.25 to 20 mA current.
Condition HART (Normal)
Run 4 ,8, 12,16, 20 mA
COPM Fault 3.5 mA
Fault 3.5 mA
EXCEPTION: If HART communication is not installed when a command is sent to the HART Current bit,
Exception Code 01 (Illegal Function) is sent back.

3.27. Input Voltage (33H)

A Read command sends back the measured input voltage. If the measured voltage is less than the
necessary 20 volts, a Low Supply Voltage fault can occur. Refer to the FL500 UV/IR Flame Detector
Operating Manual (PN 10193213) for information about troubleshooting faults.

3.28. DIP Switch Settings (36H)

A Read command sends back a digital copy of the configuration of the first eight option settings on the DIP
switch.

3.29. User Information (68H to 77H)

This section in memory lets users keep Modbus-compatible information, such as physical location or other
user identification. Only one word can be written per command. A total of 16 words are available.
Operational Mode Command Register Details
HART (Special)
4 ,8, 12,16, 20 mA
2.0 mA
1.25 mA
FL500 Modbus Communication Operating Manual
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