AN-X4-ABRIO-SCAN Page
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Scanning Remote I/O
Required Connections
If all required ControlLogix connections are not running, the AN-X4-ABRIO-SCAN scans the remote
I/O network in program mode.
Scan Mode: Program/Run
The remote I/O scan mode (program or run) is determined by the mode of the controller with the
exclusive owner connection to slot 0 of the AN-X4-ABRIO-SCAN.
In run mode, the AN-X4-ABRIO-SCAN scans remote racks, reads discrete inputs and writes discrete
outputs, and updates block transfers.
In program mode, the AN-X4-ABRIO-SCAN scans remote racks, reads discrete inputs but does not
write discrete outputs or update block transfers.
In test mode, the AN-X4-ABRIO-SCAN behaves the same as it does in program mode.
Executing Block Transfers
Automatic
An automatic block transfer performs a configuration block transfer write once and then performs
timed data block transfer read and write updates using the BTR and BTW data lengths and update
times from the configuration tool.
Automatic block transfers begin as soon as the processor is in run mode; they do not have to be
triggered.
Errors in block transfer execution are indicated by non-zero values in the BTR/BTW Error Code.
In automatic mode, the I/O module configuration data values come from the configuration tool, either
as default values or from user parameters. The size of the configuration block transfer write is the data
BTW length, BtwLen, plus the Config BTW Length, CfgLen, from the template. The data block
transfer write length is BtwLen from the template and this is the length mapped to CLX scheduled
output data.
The size of the data block transfer read is set by the configuration tool.
Semi-Automatic
A semi-automatic block transfer performs a configuration block transfer write once and then performs
timed data block transfer read and write updates using the BTR and BTW data lengths and update
times from the configuration tool.
Semi-automatic block transfers begin as soon as the processor is in run mode; they do not have to be
triggered.
Any errors in BT execution are indicated by non-zero values in the BTR/BTW Error Code.