4 (0x04) read input resgisters, 5 (0x05) write single coil, Specification – Beijer Electronics NA-9379 User Manual

Page 12

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NA-9379

Specification

Revision 1.02

FnBus PIO N/A

Page 12

3.1.4.

4 (0x04) Read Input Resgisters

This function code is used to read from 1 to approx. 125 contiguous input registers in a remote device. The Request
PDU specifies the starting register address and the number of registers. The register data in the response message are
packed as two bytes per register, with the binary contents right justified within each byte. For each register, the first byte
contains the high order bits and the second contains the low order bits.

Request

Field name

Example

Function Code

0x04

Starting Address Hi

0x00

Starting Address Lo

0x00

Quantity of Register Hi

0x00

Quantity of Register Lo

0x02

Response

Field name

Example

Function Code

0x03

Byte Count

0x04

Input Register#0 Hi

0x00

Input Register#0 Lo

0x80

Input Register#1 Hi

0x00

Input Register#1 Lo

0x00

- In case of address 0x0000, 0x0001 input register value: 0x0080, 0x0000.

3.1.5.

5 (0x05) Write Single Coil

This function code is used to write a single output to either ON or OFF in a remote device. The requested ON/OFF state
is specified by a constant in the request data field. A value of FF 00 hex requests the output to be ON. A value of 00 00
requests it to be OFF. All other values are illegal and will not affect the output.

Request

Field name

Example

Function Code

0x05

Output Address Hi

0x10

Output Address Lo

0x01

Output Value Hi

0xFF

Output Value Lo

0x00

Response

Field name

Example

Function Code

0x05

Output Address Hi

0x10

Output Address Lo

0x01

Output Value Hi

0xFF

Output Value Lo

0x00

- Output bit of address 0x1001 turns ON.

PRELIMINARY

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