RuggedCom RS400 manual Request, 0x040x03, Response, 0x10

Appendix E – ModBus Management Support and Memory Map

Appendix E – ModBus Management Support and Memory Map

ModBus management support in RuggedCom devices provides the user with a simple interface with basic status information. Support for this protocol simplifies the job of SCADA System integrators who can now easily use this feature to retrieve basic info from RuggedCom devices via a familiar protocol. Predominantly read-only status information is provided though a few writable registers exist to provide operator commands.

The PDU format defined for the ModBus protocol is

Function Code

Data

The following ModBus function codes are supported by RuggedCom for device management through ModBus:

(1)Read Input Registers or Read Holding Registers – 0x04 or 0x03 for which the Modbus PDU would look like:

Request

Function code	1	Byte	0x04(0x03)
Starting Address	2	Bytes	0x0000 to 0xFFFF
Number of Input Registers	2	Bytes	0x0001 to 0x007D

Response

Function code	1 Byte	0x04(0x03)
Byte Count	1 Byte	2 x N*
Input Registers	N*X2 Bytes

*N = Quantity of Input Registers

(2)Write Multiple Registers – 0x10

Request

	Function code	1	Byte		0x10
	Starting Address	2	Bytes		0x0000 to 0xFFFF
	Number of Registers	2	Bytes		0x0001 to 0x0079
	Byte Count	1	Byte		2 x N*
	Registers Value	N* x 2 Bytes			Value of the register
	*N = Quantity of Input Registers
Response
	Function code	1	Byte	0x10
	Starting Address	2	Bytes	0x0000 to 0xFFFF
	Number of Registers	2	Bytes	1 to 121 (0x79)

RS400 267 ROS™ v3.5