Modbus services
34 S1A53844 01/2011
Read indirect block (3)Function 3, quantity = 1 ... 5
The Read indirect block function permits to read 1 to 5 parameters. These parameters can be chosen by
parameters F875 ... F879 (refer to "Configuration of the indirect blocks", page27)
Access to the parameter
This parameter is accessible in the [COMMUNICATION MENU] COM submenu of [PROGRAMMING MENU]
Programming mode.
Description
Request:
Response:
Error response:
Example: Read indirect block in an drive with slave address 1.
Configuration parameters:
[Block read data 1] (F875) = 1: [drive Status] (Fd01)
[Block read data 2] (F876) = 2: [Output frequency] (Fd00)
[Block read data 3] (F877) = 3: [Output current] (FE03)
[Block read data 4] (F878) = 4: [Output voltage] (FE05)
[Block read data 5] (F879) = 5: [Alarm code] (FC91)
•Read indirect block of 5 parameters:
Parameters Modbus
address
Adjustment range Default
setting
Valid
after
[Block read data 1] (F875)2165
16#875
0 [No select]: No selection
1 [Status info]
2 [Freq. out]: Output frequency
3 [Motor current]: Ouput current
4 [Ouput volt]: Ouput voltage
5 [Alarm info]: Alarm information
6 [PID feedback value]
7 [Input term. mon]: Input terminal board monitor
8 [Out term. mon]: Output terminal board monitor
9 [VIA monitor]: VIA terminal board monitor
10 [VIB monitor]: VIB terminal board monitor
11 [Mot speed mon.]: Ouput motor speed monitor
0Power
cycle
[Block read data 2] (F876)2166
16#876
[Block read data 3] (F877)2167
16#877
[Block read data 4] (F878)2168
16#878
[Block read data 5] (F879)2169
16#879
Slave no. Function code Starting address Quantity of registers CRC16
03 Hi
18 (fixed)
Lo
75 (fixed)
Hi
00
Lo
02 to 05
Lo Hi
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Slave no. Function code Byte count First register value ------- Last register value CRC16
03 Hi Lo Hi Lo Lo Hi
1 byte 1 byte 1 byte 2 bytes 2 bytes 2 bytes
Slave no. Function code Exception code CRC16
83 Lo Hi
1byte 1byte 1byte 1byte
Request: 01 03 18 75 00 05 92 B3
Response: 01 03 0A 64 04 17 70 00 00 26 FB 00 80 1E 29