Manual
Table Of Contents
- Table of Contents
- 1. ENVIRONMENT SPECIFICATION
- 2. NA-9379 (FNIO MODBUS PROGRAMMABLE I/O)
- 3. MODBUS/RTU INTERFACE (NOT TCP)
- 3.1. Surpported MODBUS Function Codes
- 3.1.1. 1 (0x01) Read Coils
- 3.1.2. 2 (0x02) Read Discrete Inputs
- 3.1.3. 3 (0x03) Read Holding Resgisters
- 3.1.4. 4 (0x04) Read Input Resgisters
- 3.1.5. 5 (0x05) Write Single Coil
- 3.1.6. 6 (0x06) Write Single Register
- 3.1.7. 8 (0x08) Diagnostics
- 3.1.8. 15 (0x0F) Write Multiple Coils
- 3.1.9. 16 (0x10) Write Multiple Resgisters
- 3.1.10. 23 (0x17) Read/Write Multiple Resgisters
- 3.1.11. Error Response
- 3.2. MODBUS Special Register Map
- 3.2.1. Adapter Resgister Mapping
- 3.2.2. Adapter Identification Special Resgister (0x1000, 4096)
- 3.2.3. Adapter Watchdog Time, other Time Special Register (0x1020, 4128)
- 3.2.4. Adapter Information Special Register (0x1100, 4352)
- 3.2.5. Adapter Setting Special Register (0x1600, 5632)
- 3.2.6. Expasion Slot Information Special Resister (0x2000, 8192)
- 3.3. Surpported MODBUS Function Codes
- 3.1. Surpported MODBUS Function Codes
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