MERIDIAN
UNIVERSAL GAS DETECTOR
CONFIGURATION & SETUP
5-32
USE AND DISCLOSURE OF DATA
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prohibited.
5.4. Using the MODBUS Registers
Refer to
MODBUS Registers - Transmitter Dynamic
for details about the MODBUS registers.
MODBUS Registers - Sensor X Data
following to determine the specific MODBUS register addresses:
• the offset for Sensor1 is 4096 (base in decimal) and 1000 (base in Hex), denoted as 0x1001;
• the offset for Sensor2 is 8192 (base in decimal) and 2000 (base in Hex), denoted as 0x2001;
• the offset for Sensor3 is 12288 (base in decimal) and 3000 (base in Hex), denoted as 0x3001.
For example, to find the MODBUS register address for the data associated with GasConc for Sensor1,
MODBUS Registers - Sensor X Data
shows D0 (Hex). The offset is 1000 (Hex) + D0 (Hex) is 4096 (decimal)
+ 208 (decimal) = 4304 (decimal). Next, take 4304 (decimal) + 40001 (decimal) = 44305 which is the MOD
-
BUS register address for the GasConc for Sensor1.
EXECUTING WRITE REGISTER FUNCTIONS WILL ALTER EXTERNAL DEVICES AND THUS THEIR
BEHAVIOR. NEVER WRITE TO ANY PLC ADDRESS UNLESS YOU UNDERSTAND THE DEVICE
PERFORMANCE OR OPERATION CHANGES THAT WILL RESULT AND HAVE DETERMINED
THAT THE CHANGES WILL NOT CREATE AN UNSAFE SITUATION. ALWAYS FOLLOW THESE
GUIDELINES WHEN CHANGING MODBUS REGISTERS:
• ONLY QUALIFIED PERSONNEL SHOULD MAKE CHANGES TO MODBUS REGISTERS.
• ALWAYS TEST YOUR CHANGES IN A TEST LAB ENVIRONMENT.
• ALWAYS VERIFY YOUR MODBUS REGISTER CHANGES PRIOR TO IMPLEMENTATION IN A
FUNCTIONAL PLANT ENVIRONMENT.
• FOR REMOTE LOCATIONS, VERIFY ALL MODBUS CHANGES FUNCTION AS INTENDED
PRIOR TO IMPLEMENTATION IN A FUNCTIONAL PLANT ENVIRONMENT.
FAILURE FOLLOW THESE GUIDELINES COULD RESULT IN SERIOUS INJURY OR DEATH.
