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User Guide: LDRA6 Appendix A: Modbus Communications

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Table 6: Status Flags (Register 30008)

Bit Read Registers Response Packet

00 0 = Zone 1 Configured for Leak Detection / 1 = Zone 1 Configured for Dry Contact

01 0 = Zone 2 Configured for Leak Detection / 1 = Zone 2 Configured for Dry Contact

02 0 = Zone 3 Configured for Leak Detection / 1 = Zone 3 Configured for Dry Contact

03 0 = Zone 4 Configured for Leak Detection / 1 = Zone 4 Configured for Dry Contact

04 0 = Zone 5 Configured for Leak Detection / 1 = Zone 5 Configured for Dry Contact

05 0 = Zone 6 Configured for Leak Detection / 1 = Zone 6 Configured for Dry Contact

06-15 0

A-2.3 Present Single Register

To set a LDRA6 parameter value, the master must send a Preset Single Register request packet. The Preset

Single Register request packet specifies a register and the data to write to that register. The register is

numbered from zero (40001 = zero, 40002 = one, etc).

Table 7: Present Single Register Packet Structure

Preset Registers Request Packet Preset Registers Response Packet

Slave Address (1 byte) Slave Address (1 byte)

06 (*Function code) (1 byte) 06 (Function code) (1 byte)

Data (2 bytes) Data (2 bytes)

Crc Checksum (2 bytes) Crc Checksum (2 bytes)

A-2.4 Present Multiple Registers

To set multiple LDRA6 parameter values, the master must send a Preset Multiple Registers request packet.

The Preset Multiple Register request packet specifies a starting register, the number of registers, a byte

count and the data to write to the registers. The register is numbered from zero (40001 = zero, 40002 =

one, etc).

Table 8: Present Multiple Registers Packet Structure

Preset Registers Request Packet Preset Registers Response Packet

Slave Address (1 byte) Slave Address (1 byte)

16 (Function code) (1 byte) 16 (Function code) (1 byte)

Start Register (2 bytes) Start Register (2 bytes)

# of registers to write (2 bytes) # of registers (2 bytes)

Byte Count (1 byte) Crc Checksum (2 bytes)

Data (2 bytes)

…

Crc Checksum (2 bytes)