Instruction Manual

Bit 4 1-Alarm 1 is latching 0-Alarm 1 is non-latching

Bit 3 1-Alarm 1 Relay is energized 0-Alarm 1 Relay is not energized

Bit 2 1-Fault is normally energized 0-Fault is normally de-energized

Bit 1 1-Fault is latching 0-Fault is non-latching

Bit 0 1-Fault Relay is energized 0-Fault Relay is not energized

The following is a typical Master Query for device # 8:

Field

Name HEX DEC RTU

Slave Address 08 8 0000 1000

Function 03 3 0000 0011

Start Address Hi 00 0 0000 0000

Start Address Lo 00 0 0000 0000

No. of Registers Hi 00 0 0000 0000

No. of Registers Lo 06 6 0000 0110

CRC ## #### ####

The following is a typical Slave Response from device # 8:

Field

Name HEX DEC RTU

Slave Address 08 8 0000 1000

Function 03 3 0000 0011

Byte Count 0C 12 0000 1100

Reg40000 Data Hi 02 2 0000 0010

Reg40000 Data Lo 64 100 0110 0100

Reg40001 Data Hi 00 0 0000 0000

Reg40001 Data Lo 64 100 0110 0100

Reg40002 Data Hi 00 0 0000 0000

Reg40002 Data Lo 07 7 0000 0111

Reg40003 Data Hi 00 0 0000 0000

Reg40003 Data Lo 0A 10 0000 1010

Reg40004 Data Hi 00 0 0000 0000

Reg40004 Data Lo 14 20 0001 0100

Reg40005 Data Hi 05 5 0000 0101

Reg40005 Data Lo 50 80 0101 0000

CRC ## #### ####

Additional Notes:

The calibration LED will light when the transmitter is sending a response to a Master Query.

Communications are 9600 baud, 8 data bits, 1 stop bit, No parity, half duplex 485.

3.12 DISPLAY CONTRAST ADJUST

Model IR-622 MicroSafe™ sensors feature a 16 character backlit liquid crystal display. Like most LCDs, character

contrast can be affected by viewing angle and temperature. Temperature compensation circuitry included in the

MicroSafe™ design will compensate for this characteristic, however temperature extremes may still cause a shift in

the contrast. Display contrast can be adjusted by the user if necessary. However, changing the contrast requires that

the sensor housing be opened, thus declassification of the area is required.

To adjust the display contrast, remove the enclosure cover and use a jewelers screwdriver to turn the contrast

adjust screw located beneath the metallic face plate. The adjustment location is marked “CONTRAST”. See figure 7

for location.

Detcon Model IR-622 Combustible Hydrocarbon Sensor PG.20