User Manual

Model 1000 H2S Echem

Model 1000 H2S Echem Instruction Manual Rev. 2.8 Page 22 of 30

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, and half duplex 485.

10. Display Contrast Adjustment

Detcon 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 jeweler’s screwdriver to turn the contrast

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

11. Low Flow Fault Options

Model 1000 Analyzers offer two low flow fault option PCB’s. One monitors for low sample gas flow, and the

second monitors for low airflow dilution. The Low Flow Fault option for sample gas flow is usually set for

the relay contacts to fire at flow rates ≤ 100cc/min. The Flow Fault option for air dilution is usually set for the

relay contacts to fire at flow rates ≤ 300cc/min. These set points are factory set. Should it become necessary

to adjust the flow fault set points in the field, adjust the flow to the set point target (100 or 300cc/min.) at

rotameter(s) and adjust the potentiometer on the corresponding Low Flow Fault PCB until the fault LED

toggles between “ON” and “OFF”.