ProSoft Technology MVI56E-MCMR - Manual (Page 147)

MVI56E-MCMR ♦ ControlLogix Platform Reference
Modbus Communication Module with Reduced Data Block User Manual
ProSoft Technology, Inc. Page 147 of 225
May 13, 2014
6.2.3 General Specifications - Modbus Master/Slave
Communication
parameters Baud Rate: 110 to 115K baud
Stop Bits: 1 or 2
Data Size: 7 or 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, Daniel
® , and other implementations
Modbus Function Codes
Supported 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
8: Diagnostics (Slave Only,
Responds to
Subfunction 00) 15: Force( Write) Multiple Coils
16: Preset (Write) Multiple
Holding Registers
17: Report Slave ID (Slave Only)
22: Mask Write Holding
Register (Slave Only)
23: Read/Write Holding
Registers (Slave Only)
6.2.4 Functional Specifications
Modbus Master
A port configured as a virtual Modbus Master actively issues Modbus commands
to other nodes on the Modbus network, supporting up to 100 commands on each
port. The Master ports have an optimized polling characteristic that polls slaves
with communication problems less frequently.
Command List Up to 100 command per Master port, each fully configurable for
function, slave address, register to/from addressing and word/bit
count.
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.
Modbus Slave
A port configured as a Modbus slave permits a remote Master to interact with all
data contained in the module. This data can be derived from other Modbus slave
devices on the network, through a Master port, or from the ControlLogix
processor.
Node address 1 to 247 (software selectable)
Status Data Error codes, counters and port status available per configured slave
port