Read Holding Registers Service (4E Hex) - Comtrol DeviceMaster EtherNet/IP-Modbus EIP-MOD User Manual

| Read Holding Registers Service (4E Hex)

10.4. Read Holding Registers Service (4E Hex)
This service reads one or more holding registers from the Modbus Holding Register table. This service results
in the DeviceMaster EIP-MOD issuing a Read Holding Registers function (function code 0x03) to either the
Shared Memory or the Modbus Message Routing subsystem. Refer to CIP Standard Vol1_3.22 Section 5B-3
and/or MODBUS Application Protocol Specification V1.1b3.pdf at
Parameter
Service Code
Instance
Class
Attribute
Source Element RdHoldingRegsReqData
Source Length
Destination
DeviceMaster EIP-MOD User Guide: 2000664 Rev. A
Value
4E hex
10
44 hex
0
4
RdHoldingRegsRespData
www.modbus.org
Description
Directly corresponds to Modbus function code:
Read Input Registers (function code 3)
Modbus Device ID of 10 (Valid Range = 1 to 255)
Modbus Object
Not used
Tag of structure type RdHoldingRegsRequest
Length in bytes of RdHoldingRegsReqData
Tag of structure type RdHoldingRegsResponse
Chapter 10. PLC Programming for Modbus Object (44 Hex) - 133
for more details.