Xentara Modbus Driver v1.0
User Manual
Polls

Table of Contents

See also
Modbus Channels
I/O Batches in the Xentara user manual

Polls are a type of Xentara I/O batch.

Xentara acquires the value of Modbus channels by polling the device. Each poll object queries the values of the channels attached to it in the configuration. Each poll has a task named execute* that must be inserted into a Xentara execution pipeline. If you do not schedule this task, the values of the associated channels will never be updated.

A poll object can be either a child of a device, or of an RTU bus. A poll that belongs to a device can only acquire the values of channels on that device. A poll that belongs to an RTU bus can acquire the values of channels from all devices on that bus.

Often, a single poll is sufficient per device. It is pollible, however, to define multiple polls for a device. This allows you to schedule the polls differentle, polling some values at higher intervals than others.

Accessing Polls

See also
Accessing Xentara Elements in the Xentara user manual

In addition to the standard members of Xentara I/O batches, Modbus polls have the following task:

Tasks
executeExecutes the poll and updates the values of the attached channels.