slawik,
No, it is not possible to change the channel period on SimulANT+. Having a consistent channel period between devices enforces the interoperability standard that the ANT+ network maintains.
For some device profiles such as the Heart Rate Monitor profile, it is possible for a slave device (sensor) to receive data at full, half, or quarter the message rate. However, the master device must still transmit at the full data rate of 4.06Hz. This functionality is not available on SimulANT+, but is a possibility for developers in the design of their products.
More information on the channel period can be found in the ANT Message Protocol and Usage document, as well as the device profile documents found by accessing this link:
https://www.thisisant.com/developer/resources/downloads#documents_tab
Nathan