QK-A031 and NMEA checksum

Hi,

I ordered one of these and was impressed with how quickly it arrived.

Now in my first test I could not understand why the input LED for input 1 was not flashing when data was being sent once second.

The incoming data was coming from a device simulator not a real device. It lacked a valid NMEA checksum so strictly speaking not valid NMEA. That said it started with $ and ended with rn.

As soon as I gave it a valid NMEA message it was happy.

So I ask:

1) is it really necessary for the multiplexer to validate the NMEA checksum?

2) is there any config or firmware change to disable the checksum validation?

Why would I want this?

My client wants to use some existing 422 cabling and bring in two additional messages. One is from a Kongsberg device that for certain telegrams might be missing a checksum. The other is from a motion sensor (I have seen plenty of these that do not have a checksum field. Some even binary although I certainly would not expect binary to be supported.

While the leisure, fishing and light marine markets are far less likely to encounter devices which don’t have valid NMEA telegrams there exist numerous devices that fall into this category.

Being able to take in non-standard messages would help.