CAT EMCP 4 - 7.3 READING INVALID DATA

Application and Installation Guide EMCP 4 SCADA Data Links
©2013 Caterpillar
All rights reserved. Page 41
F
IGURE 7-3: EXAMPLE OF READING ONLY ONE REGISTER WHILE PERFORMING A 2-REGISTER READ
An alternate approach to finding the value is to find the numeric value for each register
separately, and then multiply the lower number register value by 2^16 and then add the result
to the higher number register value:
Lower register raw data in hex: 00 01
Lower register raw data in decimal: 1
Higher register raw data in hex: 12 1A
Higher register raw data in decimal: 4,634
1
× 2^16 + 4,634 = 65,536 + 4,634 = 70,170
And finally to scale with 0.05 hr / bit:
70,170
× 0.05 = 3508.5 HRS.
7.3 READING INVALID DATA
This example demonstrates reading data and receiving an invalid data response. See section 6.3 for
more information on invalid data responses. Suppose that the Engine Oil Pressure Sensor Configuration
setpoint is configured to Data Link. However, oil pressure is not being received over the data link, rather
from a sensor directly connected to an analog input on the EMCP 4.