Chapter 4 explanation of functions – Hitachi SJ700-2 User Manual

Page 200

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Chapter 4 Explanation of Functions

(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)

4 - 137

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

This query cannot be broadcasted.
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.















*1
*2





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."

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