Data transmission with modbus ascii – VEGA VEGASCAN 850 Modbus signal output User Manual
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Modbus signal output VEGASCAN 850
Start
Function
code
Address of the
1. register
word
Number of
register
words
Error
Check
End
No. of
bytes
Value
range
Meaning
Structure of the measured value enquiry Modbus master to VEGACOM 557
ASCII enquiry telegram acc. to measured values (function code 04)
1
2
2
4
4
2
2
:
1 .. 247
04
0 ... 65.509
1 ... 127
LRC
CR LF
0
Start
Function
code
Number of
data
bytes
Error
Check
End
No. of
bytes
Value
range
Meaning
Structure of the answer VEGACOM 557 to Modbus master
ASCII answer telegram (function code 04)
1
Data (DCS values)
DCS value 15 of
VEGASCAN:
Status: 0x00
Unit: 0x00
Meas. value:
0x014A
= 3.30%
1
0
4
0
0
1
C
0
0
0
2
:
X
X
CR
LF
0
1
0
4
0
4
0
1
4
A
:
X
X
CR
LF
:
2
2
2
8 (per DCS value)
2
2
1 .. 247
04
2 ... 254
LRC
CR LF
0
0
0
0
Data transmission with Modbus ASCII
Setting of parameters of VEGASCAN 850 in ASCII mode
Various parameters of VEGASCAN can be enquired measurement loop related.
The following list gives an overview of the parameters involved:
Parameter name
possible access mode
Integration time
reading
writing
Scaling (0 %)
reading
writing
Scaling (100 %)
reading
writing
The enquiry or modification of parameters via the Modbus is made with the function codes 16
(= Preset Multiple Registers) and 04 (Read Input Registers).
Slave
ad-
dress
Slave
ad-
dress