The CAT firmware in many Icom radios (e.g. IC-9100 and many others) do not have a command to directly read the VFO B frequency.

This is something that has been brought to Icom’s attention many times in the past. Since these radios are not capable of providing this data it makes them very unsuitable for satellite tracking.

Look at the CI-V commands in the back of your manual and you will understand what is being said. There are commands to swap VFO A to B and vice versa. But you may find there is no command to directly read and set VFO B.

Some ham radio software packages provide a pseudo capability by switching from VFO A to VFO B, read the frequency, load that data into a buffer and swap back to VFO A. It then uses the data in the buffer to display VFO B. The problem with this is there is a certain amount of latency, or delay, while both the radio and the software perform this function. It will also interrupt your audio for a split second while it swaps VFO A/VFO B, which, depending on mode, would be rather intrusive.

Imagine trying to ear copy CW while every 3 seconds (or whatever the update rate is) you drop a few dits or dahs while this polling is happening (Fast AGC would also be necessary). This practice in programming is called a kludge or work-a-round.

One radio manufacturer has already confronted HRD LLC about the use of kludges to access features that were not in the actual CAT Command Set, and have ordered us to stop this practice.

Therefore, HRD LLC has adopted the policy not to use kludges like this as in many cases it requires reading/writing to the EEPROMS within the radio itself. The reasoning behind this is simple. EEPROMS have a life-cycle. In other words, they can withstand only a certain number of read/write cycles. Once this limit is reached, the EEPROM becomes useless and could actually make your radio inoperable.