70
DENT Instruments
PowerScout HD
RTU Programming & Scripting
String example 1: Change a Static IP Address
Change the IP address of a meter from 192.168.2.8 to 192.168.2.9
It may be tempting to update only the digit “8” to “9” in the IP address, but this will NOT perform as
expected. Internally, the meter uses a single string buffer for all string register operations and
unspecified entrees will continue to contain the previous buffer contents unless specifically written to.
Write every register from the beginning of the block to the end.
Reg (dec)
1079
1080
1081
1082
1083
1084
1085
1086
Reg (hex)
04 37
04 38
04 39
04 3A
04 3B
04 3C
04 3D
04 3E
Value (Chr)
‘1’ ‘9’ ‘2’ ‘.’ ‘1’ ‘6’ ‘8’ ‘.’ ‘2’ ‘.’ ‘9’ NUL NUL NUL NUL NUL
Value (hex)
31 39
32 2E
31 36
38 2E
32 2E
39 00
00 00
00 00
START
STOP
Specific Implementation Examples – Element A set to ID 1
Note that in Modbus the CRC communicated is LSB then MSB.
VIA MODBUS RTU (SERIAL) USING FUNCTION CODE 6 / WRITE SINGLE REGISTER
ID FC ADDR DATA CRC
01 06 04 37
31 39
EC B6
01 06 04 38
32 2E
9C 4B
01 06 04 39
31 36
CD 71
01 06 04 3A
38 2E
3B 2B
01 06 04 3B
32 2E
6C 4B
01 06 04 3C
39 00
5A A6
01 06 04 3D
00 00
19 36
01 06 04 3E
00 00
E9 36
VIA MODBUS RTU (SERIAL) USING FUNCTION CODE 16 / WRITE MULTIPLE REGISTER
ID FC ADDR #REGS LN DATA0 DATA1 DATA2 DATA3 DATA4 DATA5 DATA6 DATA7 CRC
01 10 04 37 00 08 10
31 39 32 2E 31 36 38 2E 32 2E 39 00 00 00 00 00
9B 99
VIA MODBUS TCP (ETHERNET) USING FUNCTION CODE 6 / WRITE SINGLE REGISTER
TXNID PROID LENGT ID FC ADDR DATA
(TXNID will be arbitrary)
01 87 00 00 00 06 01 06 04 37
31 39
01 88 00 00 00 06 01 06 04 38
32 2E
01 89 00 00 00 06 01 06 04 39
31 36
01 8A 00 00 00 06 01 06 04 3A
38 2E
01 8B 00 00 00 06 01 06 04 3B
32 2E
01 8C 00 00 00 06 01 06 04 3C
39 00
01 8D 00 00 00 06 01 06 04 3D
00 00
01 8E 00 00 00 06 01 06 04 3E
00 00
VIA MODBUS TCP (ETHERNET) USING FUNCTION CODE 16 / WRITE MULTIPLE REGISTER
TXNID PROID LENGT ID FC ADDR #REGS LN DATA0 DATA1 DATA2 DATA3 DATA4 DATA5 DATA6 DATA7
01 87 00 00 00 17 01 10 04 37 00 08 10
31 39 32 2E 31 36 38 2E 32 2E 39 00 00 00 00 00
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