MBS Protocol
PLX3x Series ♦ Multi-Protocol Gateways
User Manual
Page 116 of 215
ProSoft Technology, Inc.
January 25, 2018
7.1.1 Modbus Serial Specifications
Command List
Up to 100 commands per Master port, each fully configurable for
Function Code, slave address, register to/from addressing and word/bit
count.
Supported Modbus
Function Codes
1: Read Coil Status
2: Read Input Status
3: Read Holding Registers
4: Read Input Registers
5: Force (Write) Single Coil
6: Preset (Write) Single Holding Register
15: Force (Write) Multiple Coils
16: Preset (Write) Multiple Holding Registers
Polling of Command
List
Configurable polling of command list, including continuous and on
change of data, and dynamically user or automatic enabled.
Status Data
Error codes available on an individual command basis. In addition, a
slave status list is maintained per active Modbus Master port.
Node Address
1 to 247 (software selectable)
RS Interface
RS232, RS422, and RS485
7.1.2 Modbus Master/Slave Port Specifications
Type
Specifications
General Parameters
Internal Database
Up to 4000 registers (words) available.
Communication
parameters
Port 0: Baud Rate: 110 to 115K baud
Port 1, 2, 3: Baud Rate: 110 to 115K baud
Stop Bits: 1 or 2
Data Size: 5 to 8 bits
Parity: None, Even, Odd RTS Timing delays: 0 to 65535 milliseconds
Modbus Modes
RTU mode (binary) with CRC-16
ASCII mode with LRC error checking
Floating Point Data
Floating point data movement supported, including configurable support
for Enron implementation
