Writing The Control Program, 32 Input Mode; Multiple Active Channels - Automation Direct DL405 User Manual

Writing the Control Program, 32 Input Mode

If you have configured the F4–04AD module for 32 Input mode, use the following
examples to get started writing the control program (for modules configured in 16
Input mode, go back to the section titled "Writing the Control Program, 16 Input
Mode").
The analog data is multiplexed into the lower word. It is presented in either 12 or 16
Multiple Active
bits, depending on the range and format selected. In the 12-bit format modes, the
Channels
upper 4 bits are always 0000. The upper word contains three groups of bits that
contain active channel status, sign bit information, and broken transmitter status.
Each bit group contains one bit for each channel. The upper four bits are unused,
and are always 0000.
The control program must determine which channel's data is being sent from the
module. If you have enabled only one channel, its data will be available on every
scan. Two or more channels require multiplexing the lower data word. Since the
module communicates as X input points to the CPU, it is very easy to use the active
channel status bits in the upper word to determine which channel is being
monitored.
Unused Bits
V40402
MSB
X X X
5 5 4
7 0 7
Broken Sign
(always Transmitter Bits
0000) Bits
F4–04AD 4 Channel Analog Input
F4-04AD
8pt 8pt 32pt 16pt
Input Input Input Input
X0 X10 X20 X60
– – – –
X7 X17 X57 X77
V40400 V40403
V40401
LSB MSB
X X
4 3
0 7
Active Data word contains 12 or 16 data
Channel bits (format-dependent)
bits
3–27
16pt 16pt
Output Output
LSB
X X X
3 2 2
0 7 0