Functioning IP/IE3112

The analog input module handles signals from 0 to 20 mA with a resolution of 16 bits. The filter constants and the associated conversion times can be adjusted over a wide range.

Process data (hex)	Process data (decimal)	Measured value
0x0000	0	0 mA
0x3FFF	16383	10 mA
0x7FFF	32767	20 mA

As from software version [IP3112-Bxxx "3"; IE3112 "0"] (see Appendix) it is also possible to set the range from 4..20 mA in register 32 (bit 5 = 1). This setting in the feature register can be set separately for each channel.

Process data (hex)	Process data (decimal)	Measured value
0x0000	0	4 mA
0x3FFF	16383	12 mA
0x7FFF	32767	20 mA

Representation corresponds to the INT (integer) number format. The default setting is for the process data to be entered in twos complement (-1 corresponds to 0xFFFF).

Process data

The process data written by the controller is output as follows:
x_adc = output value from the A/D converter
y_aus = process data to the PLC controller
B_a, A_a = manufacturer scaling (registers 17, 18)
B_h, A_h = manufacturer scaling (registers 19, 20)
B_w, A_w = user scaling (registers 33, 34)
Y_dac = output value to the D/A converter

Neither user nor manufacturer scaling are active

Y_a = (B_a + x_adc)*A_a
Y_aus = Y_a

Manufacturer scaling active (default)

Y_1 = B_h + A_h * Y_a
Y_aus = Y_1

User scaling active

Y_2 = B_w + A_w * Y_a
Y_aus = Y_2

Manufacturer and user scaling active

Y_1 = B_h + A_h * Y_a
Y_2 = B_w + A_w * Y_1
Y-aus = Y_2
The linear equations are activated via register 32.