Channel Scanning Sequence - Automation Direct DL405 User Manual

Channel Scanning
Sequence
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.
The D4–02DA module updates both channels in the same scan. The control
program updates the two channels of this module independent of each other and
each channel does not have to be refreshed on every scan.
Scan
Read inputs
Execute Application Program
Calculate the data
Write data
Write to outputs
D4-02DA 2-Channel Analog Output
Scan N
Scan N+1
Scan N+2
Scan N+3
Scan N+4
11–7
Channel 1
Channel 2
Channel 1
Channel 2
Channel 1
Channel 2
Channel 1
Channel 2
Channel 1
Channel 2