Automation Direct DL405 User Manual page 365

Before you begin writing the control program, it is important to take a few minutes to
understand how the module processes and represents the analog signals.
Channel The F4–04DAS–2 module allows you to update the channels in any order. Your
control program determines which channel gets updated on any given scan by
Scanning
Sequence using two binary encoded output points. With a D4–440 or D4–450 CPU, you can
use immediate instructions to update all four channels in the same scan (we will
show you how to do this later).
Output Bit You may recall the F4–04DAS–2 module requires 32 discrete output points from
the CPU. These points provide:
Assignments
Since all output points are automatically mapped into V-memory, it is very easy to
determine the location of the data word that will be assigned to the module.
F4–04DAS–2 4-Channel Isolated 0–5V, 0–10V Output
Scan
Read inputs
Execute Application Program
Calculate the data
Write data
Write to outputs
S
The digital representation of the analog signal.
S
Identification of the channel that is to receive the data.
Scan N Channel 1
Scan N+1 Channel 2
Scan N+2 Channel 3
Scan N+3 Channel 4
Scan N+4 Channel 1
18–7