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

execute Executes the poll and updates the values of the attached channels.

Table of Contents

Accessing Polls