RLE LD1500 V.3.1 - Manual (Page 39)

rletech.com LD1500 User Guide 39
5 Modbus Communication
5.2. Packet Communications for the LD1500
5.2.1 Function 03: Read Output Registers
To read the LD1500 parameter values, the master must send a Read Output Registers request
packet.The Read Output Registers request packet specifies a start register and the number of
registers to read. The start register is numbered from zero (40001 = zero, 40002 = one, etc).
Table 5.2 Read Output Registers Packet Structure
Read Registers Request Packet Read Registers Response Packet
Slave Address (1 byte) Slave Address (1 byte)
03 (Function code) (1 byte) 03 (Function code) (1 byte)
Start Register (2 bytes) Byte count (1 byte)
# of registers to read (2 bytes) First register (2 bytes)
CRC Checksum (2 bytes) Second register (2 bytes)
…
CRC Checksum (2 bytes)
Table 5.3 Output Registers
Register Name Description Range, Units Range
40001 Leak Threshold Trip current for leak alarm 25-295 μ Amps 0-65535
40002 Contamination Threshold Trip current for
contamination alarm
20-295 μ Amps 0-65535
40003 Spare 0-65535
40004 Spare 0-65535
40005 Spare 0-65535
40006 Spare 0-65535
40007 Spare 0-65535
40008 Spare 0-65535
40009 Spare 0-65535
40010 Spare 0-65535
40011 Spare 0-65535
40012 Spare 0-65535
40013 Spare 0-65535
40014 Spare 0-65535
40015 Spare 0-65535
40016 Leak Alarm Delay Leak Alarm Delay 5-995 seconds 0-65535
40017 Contamination Alarm Delay Contamination Alarm Delay 5-995 seconds 0-65535