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Chapter 4 Explanation of Functions
4 - 134
(ii) Reading registers [03h]
This function reads a specified number of registers beginning at a specified register address.
(Example)
When reading the trip history data from the inverter at slave address "5":
Assume that the conditions of the past three trips are as follows:
SJ700 command d081 (factor of most recent trip) d081 (inverter state at most recent trip)
Register number 0012h 0013h
Trip factor (upper digit) Overvoltage (E07) Decelerating (02)
Read the data received in the response as follows:
Response buffer 4 5 6 7
Starting register number
+0 (upper
digit)
+0 (lower
digit)
+1 (upper
digit)
+1 (lower
digit)
Response data 00h 07h 00h 02h
Trip condition Trip due to overvoltage Decelerating
If the function to read registers cannot be executed normally, the inverter will return an exception response.
For details, see Item (viii), "Exception response."
Query
Field name Sample setting
(hexadecimal)
1 Slave address (*1) 05
2 Function code 03
3 Starting register number
(upper digit) (*2)
00
4 Starting register number
(lower digit) (*2)
11
5 Number of registers (upper
digit)
00
6 Number of registers (lower digit) 02
7 CRC-16 code (upper digit) 95
8 CRC-16 code (lower digit) 8A
*1 This query cannot be broadcasted.
*2 Note that the starting coil number is 1 less than the
actual coil number of the coil to be read first.
Response
Field name Sample setting
(hexadecimal)
1 Slave address 05
2 Function code 03
3 Number of data bytes (*3) 04
4 Starting register number
(upper digit)
00
5 Starting register number
(lower digit)
07
6 Starting register number + 1
(upper digit)
00
7 Starting register number + 1
(lower digit)
02
8 CRC-16 code (upper digit) 36
9 CRC-16 code (lower digit) 37
*3 The data equivalent to the specified number of data
bytes is transferred. In this example, 4 bytes are
transferred because the data on two registers is
returned in the response.