Requesting Parameters Using Modbus - GE XGS868 Programming Manual

November 2004
Requesting Parameters
Using MODBUS
Table 1-13: MODBUS Registers for a 1-Channel XGS868
MODBUS DPR
Reg # Hex Addr
1 0
2 2
3 4
5 8
7 C
9 10
11 14
13 18
14 1A
16 1E
18 22
20 26
21 28
23 2C
24 2E
26 32
28 36
30 3A
32 3E
34 42
508 3F6
509 3F8
510 3FA
511 3FC
512 3FE
1-38
To request specific parameters from the XGS868 via the MODBUS,
the control system must enter the appropriate register number. Only
registers 1 through 90 are available for MODBUS communications,
while registers 508 through 512 are used by the XGS868 to store the
MODBUS parameters. For details, see Table 1-13 below for a
1-Channel meter or Table 1-14 on the next page for a 2-Channel
meter.
Note: If you request Channel2 or Averaged data from a 1-Channel
meter, the values will all be zero.
Description
1
"Clear Ch1 Totalizers"
Not Used
Velocity
Act Volumetric
Std Volumetric
Fwd Totals
Rev Totals
#Tot Digits
Mass Flow
Fwd Mass Totals
Rev Mass Totals
#Mass Tot Digits
Timer
Error Code
Sound Speed
Steam Density
Signal Strength Upstream
Signal Strength Downstream
Temperature
Pressure
2
MODBUS baud rate
3
MODBUS parity
4
MODBUS stop bits
MODBUS meter addr
RESERVED
Scaling
(decimal places) Size in Bytes
-- 2 (16 bit signed)
-- 2 (16 bit signed)
2 4 (2 16-bit int)
#Q DIGITS 4 (IEEE 32 bit)
#Q DIGITS 4 (IEEE 32 bit)
#T DIGITS 4 (2 16 bit int)
#T DIGITS 4 (2 16 bit int)
0
#M DIGITS 4 (IEEE 32 bit)
#MT DIGITS 4 (2 16-bit int)
#MT DIGITS 4 (2 16-bit int)
0
2 4 (2 16-bit int)
0
3 4 (2 16-bit int)
4 4 (2 16-bit int)
1 4 (2 16-bit int)
1 4 (2 16-bit int)
2 4 (2 16-bit int)
3 4 (2 16-bit int)
0
0
0
0
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Programming Site Data
2
2
2
2
2
2
2
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