Determine how often to update data – Rockwell Automation 1789-L10_L30_L60 SoftLogix 5800 System User Manual User Manual

Page 187

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Rockwell Automation Publication 1789-UM002J-EN-P - December 2012

187

Communicate with Devices on a DeviceNet Network

Appendix A

The rack-optimized connection creates a DINT element for each possible I/O
module connected to the device in slot 3, ‘Local:3.’ The array Local:3:I.Data
contains the possible input elements; the Local:3:O.Data contains the possible
output elements.

The index number on the array element refers to the same numbered word
mapped to the device in RSNetWorx for DeviceNet. Depending on the device,
there can be several words mapped to one device. You can create aliases to the
elements you actually use to more accurately identify the data you need.

Determine How Often to Update Data

When you configure the 1784-PCIDS card, you can specify a requested packet
interval (RPI) time. The RPI you set specifies the maximum amount of time
between data updates.

The 1784-PCIDS card supports an RPI range of 2.0…750.0 ms. The default
is 5.0 ms.

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