GE Industrial Solutions ASTAT XT - Manual (Page 90)

90 • Appendix A - MODBUS RTU Protocol
Parameter # (3x) # (4x) Comment
Last Fault
24 280 # of the fault that caused trip.
# Fault
01
Over Temperature
02 Short Cir. Curr.
03 Overload
04 Under Current
05 Under Voltage
06 Over Voltage
07 Phase Loss
08 Phase Sequence
09 Shorted Scr
10 Long Start Time
11 Slow Speed Time
12 Wrong Connection
13 External Fault
14 Wrong Parameters
15 EMI/RFI Fault
16 Too Many Starts
17 Reserved
18 Thermistor.
19 Frequency
Motor FLT Current 25 281 Current at trip time, % of Im.
Reserved 26..36 282..292
Thermal Capacity 37 293
Reserved 38..108 293..364
Actual_Data_Group 109..128 365..384 Group of 20 actual parameters selected by
parameter settings 90..109
Example 1:
To read actual parameters 2 and 3 (Motor Current and Mains Voltage Actual Parameters, Addressed as 1 and 2) of
ASTAT-XT # 18 (its SERIAL LINK NO. = 18), the host computer should send following frame:
Another Possibility
(Modbus Plus users)
byte 1: Serial Link No. ($12) ($12)
byte 2: Function ($04) ($03)
byte 3: Starting Address High ($00) ($01)
byte 4: Starting Address Low ($01) ($01)
byte 5: No. of Points High ($00) ($00)
byte 6: No. of Points Low ($02) ($02)
byte 7: CRC_Low ($XX) ($XX)
byte 8: CRC_High ($XX) ($XX)
The ASTAT-XT response, when Current = 400 % of Im, and Voltage = 420V, is:
byte
1:Serial Link No. ($12) ($12)
byte 2: Function ($04) ($03)
byte 3: Byte Count ($04) ($04)
byte 4: Data High, parameter 2 ($01) (400) ($01)
byte 5: Data Low, parameter 2 ($90) ($90)
byte 6: Data High, parameter 3 ($01) (420) ($01)
byte 7: Data Low, parameter 3 ($A4) ($A4)
byte 8: CRC_Low ($XX) ($XX)
byte 9: CRC_High ($XX) ($XX)
Note:
$XX indicates Hexadecimal byte.