Hitachi SJ Series, User Manual

Page: 503 / 786

14-12
Chapter 14 RS485 Communication
14.4.2 Reading out the content of retention
register [03h]
• Read out the contents of consecutive retention registers
as much as specified, from the specified retention
register addresses.
(Example)
To read out a past trip history from the inverter with slave
address 5.
(To read out the factors and output frequency of trip monitor
1.)
----
Query
Field Name Example (HEX)
1 Slave address *1) 05
2 Function code 03
3 Register starting No. (high) *2) 03
4 Register starting No. (low) *2) E8
5
The number of retention
registers (high) 00
6
The number of retention
registers (low) 03
7 CRC-16 (high) 84
8 CRC-16 (low) 3F
*1) A broadcasting cannot be executed.
*2) Note that the value of starting number is one less than
the actual number.
Specify the value of “(Register No.)
-
1”.
*3) Data as much as the number of data bytes is
transferred. In this example, two retention registers are
returned; hence 4 bytes.
• The data received as a response is read as shown below.
• When a readout of retention register contents cannot be
executed normally, see “3.9 Exceptional Responses”.
Response
Field Name Example (HEX)
1 Slave address 05
2 Function code 03
3 Data bytes *3) 06
4 Register starting No. (high) 00
5 Register starting No. (low) 07
6 Register starting No. +1 (high) 00
7 Register starting No. +1 (low) 00
8 Register starting No. +2 (high) 17
9 Register starting No. +2 (low) 70
10 CRC-16 (high) A8
11 CRC-16 (low) 61
Trip monitor 1 (factor) Trip monitor 1 (output frequency)
Retention register No. 03E9h 03EAh, 03EBh
Data Overvoltage (E007) (0007h) 60.00Hz (0000h, 1770h)
Response buffer 4 5 6 7 8 9
Retention register starting No. +0 (hi) +0 (lo) +1 (hi) +1 (lo) +2 (hi) +2 (lo)
Response data 00h 07h 00h 00h 17h 70h
Trip description
Overvoltage trip
(0007h)
Trip frequency 60.00Hz
(00001770h)
!
A