ICP DAS USA HRT-710, Руководство пользователя

Страница: 84 / 104

HRT-710 User Manual (Version 1.24, June/2015) PAGE: 84
Send Modbus Command : 01 04 02 6A 00 0D 10 6B
Get Response : 01 04 1A 00 00 A1 41 22 01 3E 0C C5 C5 20 B0 B6 41 C0 78 42 39 91
C9 00 C5 00 00 00 00 E5 B0
Figure 6-2 Receive HART Command 3 data
(5) Parse the modbus response data.
Response Data => 01 04 1A
00 00 A1 41 22 01 3E 0C C5 C5 20 B0 B6 41 C0 78 42 39 91
C9 00 C5 00 00 00 00 E5 B0
Register data =>
00 00 A1 41 22 01 3E 0C C5 C5 20 B0 B6 41 C0 78 42 39 91 C9 00 C5 00 00 00 00
Because the unit of HART-
710’s database is byte and the unit of Modbus register is word
and the Modbus register is composed of data
base’s byte and the order is low byte first.
(For example : Modbus register0 = 0x3412, database byte0 = 0x12, byte1 = 0x34).
So we need to change the byte order. So the data will be as below.
00 00 41 A1 01 22 0C 3E C5 C5 B0 20 41 B6 78 C0 39 42 C9 91 C5 00 00 00 00 00
About the format of HART Command 3, it is shown as below.
Command 3: Read Dynamic Variables and P.V. Current
Request data bytes : None
Response data bytes : 2+24 = 26
Index format description
Byte 2~5
: float Primary Variable Current