Spectrum Controls 1746sc-INI4vi - Manual (Page 53)

Verifying Calibration
Read this chapter to verify your module’s calibration.
To verify your module’s calibration, you need:
• a precision input source whose accuracy is better than or equal to
±
1 mV on a 10 V scale and
±
0.5
µ
A on a 20 mA scale (such as an
Electronic Development Corporation Programmable IEEE 488 GP-IB
DC Calibrator, Model 521)
• programming equipment, such as an Allen-Bradley Hand-Held
Terminal (HHT) or personal computer
• Allen-Bradley Advanced Programming Software (APS) or equivalent
Your module automatically calibrates a channel after it is successfully
configured. It also calibrates a channel every 10 seconds if auto-
calibration is enabled (see Chapter 4). For these reasons, your module
should never need calibration. You may, however, want to verify the
calibration periodically using the procedures provided in this chapter.
Recommended
Schedule
Although not required, you should verify your module’s calibration once
a year or after any system failure that may have been due to input
inaccuracy.
Verifying Current Inputs 1. Configure your module for 0–20 mA input on all 4 channels using the
following configuration word values:
Address Binary Value Decimal Equivalent
O:e.0 0000 0000 0010 1001 41
O:e.1 0000 0000 0010 1001 41
O:e.2 0000 0000 0010 1001 41
O:e.3 0000 0000 0010 1001 41
e = slot number
Appendix A