Application and Installation Guide EMCP 4 SCADA Data Links
©2013 Caterpillar
All rights reserved. Page 39
F
IGURE 7-1: EXAMPLE OF OMITTING SCALING AND OFFSET WHILE PERFORMING A SINGLE REGISTER
GENERATOR OVERALL POWER FACTOR
Request: 0x 01 03 00 66 00 01 xx xx
0x 01 = slave address of EMCP 4
0x 03 = function code (Read Registers)
0x 00 66 = Generator Overall Power Factor
0x 00 01 = register count (1 register)
Response: 0x 01 03 02 80 00 xx xx
0x 01 = slave address of EMCP 4
0x 03 = function code (Read Registers)
0x 02 = byte count (2 bytes = 1 register)
0x 80 00 = 32768. 32768 × (1 / 16384) - 1.0 = 1.0 PF
7.2 TWO-REGISTER DATA READS
Two-register data points are always treated as 4-byte unsigned integers. Take this example of reading
Engine Operating Hours, registers 204-205:
Request: 0x 01 03 00 CB 00 02 xx xx
0x 01 = slave address of EMCP 4
0x 03 = function code (Read Registers)
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