MSC-3 Instruction Manual
Holding Registers (write)
Address Holding Register ID Minimum Maximum Scaling Units
0 COMMS_REF -100.0 100.0
x 10
%
1 F100 PRESET 1 -100.0 100.0
x 10
%
2 C030 ACCEL TIME 0.5 600.0
x 10
sec
3 C031 DECEL TIME 0.5 600.0
x 10
sec
4 C032 S TIME 0.01 40.00
x 10
sec
5 D01 CURRENT LIM 22% of model
current rating
125% of model
current rating
x 10
A
6 E030 ARs ALLOWED 0 15
7 E031 AR CLR TIME 0 1200
8 G050 UNDER SPEED -100.0 100.0
x 10
%
9 G051 OVER SPEED -100.0 100.0
x 10
%
The "Scaling" instruction of this table will convert a decimal value in the given units to a raw signed 16
bit integer.
Function Codes
• Function Code 01: Read Coils
• Function Code 02: Read Discrete Inputs
• Function Code 03: Read Holding Registers
• Function Code 04: Read Input Registers
• Function Code 05: Write Single Coil
• Function Code 06: Write Single Register
• Function Code 07: Read Exception Status
• Function Code 08: Diagnostics, Sub Codes 0,2,10…18,20
• Function Code 15: Write Multiple Coils
• Function Code 16: Write Multiple Holding Registers
• Function code 43: Read device Identication, Sub Code 14
The function codes supported are explained in detail in the document entitled “MODBUS Application
Protocol Specication V1.1b”. Available from http://www.modbus.org. Implementation options and
constraints of the MSC-3 are explained in the following sections.