Appendix
A.3 MODBUS
SENTRON PAC4200
226
System Manual, 09/2009, A5E02316180B-02
NOTICE
Error in the case of inconsistent access to measured values
Please ensure the start offset of the register is correct when making read accesses.
Please ensure the start offset and the number of registers are correct when making write
accesses.
If a value consists of two registers, a read command applied in the second register, for
example, will generate an error code. SENTRON PAC will also output an error code if, for
example, a write operation ends in the middle of a multi-register value.
Table A- 1
Measured variables available without a time stamp
Offset Number of
registers
Name
Format
Unit
Value range
Access
1
2
Voltage a-n
Float
V
-
R
3
2
Voltage b-n
Float
V
-
R
5
2
Voltage c-n
Float
V
-
R
7
2
Voltage a-b
Float
V
-
R
9
2
Voltage b-c
Float
V
-
R
11
2
Voltage c-a
Float
V
-
R
13
2
Current a
Float
A
-
R
15
2
Current b
Float
A
-
R
17
2
Current c
Float
A
-
R
19
2
Apparent Power a
Float
VA
-
R
21
2
Apparent Power b
Float
VA
-
R
23
2
Apparent Power c
Float
VA
-
R
25
2
Active Power a
Float
W
-
R
27
2
Active Power b
Float
W
-
R
29
2
Active Power c
Float
W
-
R
31
2
Reactive Power a (VARn)
Float
VAR
-
R
33
2
Reactive Power b (VARn)
Float
VAR
-
R
35
2
Reactive Power c (VARn)
Float
VAR
-
R
37
2
Power Factor a
Float
-
0 ... 1
R
39
2
Power Factor b
Float
-
0 ... 1
R
41
2
Power Factor c
Float
-
0 ... 1
R
43
2
THD Voltage a-b
Float
%
0 ... 100
R
45
2
THD Voltage b-c
Float
%
0 ... 100
R
47
2
THD Voltage c-a
Float
%
0 ... 100
R
49
2
Reserve
R
51
2
Reserve
R
53
2
Reserve
R
55
2
Line Frequency
Float
Hz
45 ... 65
R
57
2
3-Phase Average Voltage ph-n
Float
V
-
R
