System Exclusive Checksum

I thought I would provide some information on this topic since I have not found any reference to it on Morningstar forums.
Checksum is part of the system exclusive message that some manufacturers implement in MIDI SysEx. It is included just before the end of SysEx, F7. What it does is do a check with some calculations to make sure that the data string goes through intact. It does a calculation that includes the address and the data values. I will not go into details with the calculations. It can be found on the web.
I found out with much effort and research that if your equipment (mine is a synthesizer) requires a checksum in the SysEx, make sure it’s included otherwise the message will not be accepted by your equipment. It also needs to be added to the length (size) of the message on MC6 Preset. The MC6 will transmit the SysEx message that has a checksum in it.

That’s right. It depends on whether the the device manufacturer requires it, and different manufacturers would have their own way of calculating the checksum, or where to place it.

Here’s a good example: MIDI SysEx - Fractal Audio Wiki

Basically, if the device requires you to send F0 xx xx xx xx xx checksum F7, then you’ll need to follow that format if you want it to respond.

Hi James,
Thanks for the link. I was not sure that some guitar equipment manufacturer use the checksum. Confirmed.
Cheers,
Pete