Advantech Adam 4000 Series User Manual page 38

Function Description for the ADAM-4011 Thermocouple Input Module
To provide a better understanding of the ADAM module functions, the following is a
description of the module ADAM-4011 with the most extensive set of functions.
All analog input data first flow through the PGA (programmable gain amplifier). The
amplifier can vary its gain from 1 to 128. The PGA then automatically adjusts the sig-
nal to a range from -2.5 V to +2.5 V.
This ensures an optimal input voltage and resolution for the A/D converter.
The A/D conversion is supervised by the microprocessor that holds the calibration
software. Two kinds of calibrations, Auto Zero and Auto Span calibrations, take place
automatically in startup or reset. Normal calibration is used to adjust the signal
according to calibration parameters defined by the user.
The digital 10 Hz filter provides a steady state output by using the ∆ function.
Before the data enter the microprocessor, they pass through an optical isolation
device which prevents the chance of circuit damaging caused by power surges from
the ground terminal.
The microprocessor has six basic functions:
- Linearization of T/C (Thermocouple)
- Communication software and command set
- Calibration software
- Alarm monitoring
- Event counting
- Management of the EEPROM device that holds the system parameters
- Data transformation
After data have been transformed to the right data format, they are being passed on
to the RS-485 output port.
If an input value exceeds the High alarm setting or falls below the Low alarm setting,
a flag is set in one of the Digital Output channels.
Finally, the on-board switching regulator accepts voltage between +10 and +30 V ,
DC
and it has an isolation value of 500 V to protect your equipment from damages
DC
caused by power surges.
ADAM-4000 Series User Manual 24