FT-991A CAT Documentation Issues

The Yaesu FT-991A's CAT appears to have been written by committee. This may be due to the radio's firmware. The documentation is not 100% accurate. Its proof-reading could have been better. This page documents the various issues I have discovered.

EX018/EX022 The parameter for these arguments can be a 0 for text or 1 for message. That is all which is written in the CAT documentation. The operating manual clarifies the command. Text messages are entered via the TFT keyboard or via the CAT. The 1 indicates the message was entered using a keyer.
KY This command takes one of ten possible arguments. The arguments are 1 thru 9 and the letter 'A.' This isn't a major issue but using zero thru nine would be a simplification.

The fact there are 10 arguments but only 5 memories might be confusing to some. Under the hood there is a flag which is set when the message is stored. How the message is played back depends on whether it was entered from a keyboard or keyer. Entering a keyer message using the parameter '6' will overwrite whatever was previously written to the memory number 1. See EX018-022.

To enter a message using the KY command, the message numbers's EX command should be sent as 'EX0.'

The operator's manual indicates a closing curly brace aka '}' should be used at the end of the message. If the message is exactly 50 characters do not add the symbol as it will be the 51st character of the message. Messages are limited to 50 characters.

MR According to the documentation the three digits of the command should be the number of the memory channel to be read. Experience indicates the CAT does not honor the parameter. Instead the command will return data about the current memory channel. Even so the number must be a valid memory channel.

If a memory channel has not been written to, it will not be read.

MW The documentation indicates the P7 argument of the command is fixed as '00.' The argument is a fixed '0.'
NA The command should use 'NA' rather than the documented 'MA.'
UP Microphone up button