eHam Forums => Computers And Software => Topic started by: MM1APX on September 25, 2003, 06:11:07 PM

Title: CAT interface - polling rate
Post by: MM1APX on September 25, 2003, 06:11:07 PM
Is there any disadvantage (either to the PC or the tranceiver) in setting the "polling" on the CAT interface to a very short period of time ? ie, so that the PC checks the radio more often ?

The setting within my software is currently set to 2000ms.

Title: CAT interface - polling rate
Post by: AA6YQ on September 27, 2003, 04:41:08 AM
That depends on your transceiver, your PC, and the speed of the link between them.

Some transceivers send a lot of data; on a slow serial link, you'd need a low poll rate. Other transceivers encode the data efficiently and support fast serial port speeds, in which case you can poll more rapidly.

Increasing the polling rate will impact two microprocessors: the one in your transceiver, and the one in your PC. You can use the Windows Task Manager to measure the latter's utilization. The faster you poll, the less of your PC's CPU is available for other activities, e.g. callbook lookups or PSK or logging or propagation prediction. Your transceiver's microprocessor could also be a bottleneck, though manufacturers tend to prevent this by limiting the serial port speed.

Icom transceivers can be set to automatically send frequency and mode updates without polling. Set the CI-V Transceive parameter to "on". This gets you smooth tuning with no polling.

In my experience, polling faster than 200ms doesn't produce appreciable improvements in tuning smoothness.


        Dave, AA6YQ