[Deleted User] Posts: 0
Has anyone had experience using RS-232 for the Sherwood Newcastle R-965? Their protocol manual (http://www.sherwoodamerica.com/pdf/SherwoodRS-232protocol.pdf) is very hard to follow, and the technical support guy is clueless when it comes to RS-232, any help would be appreciated.
The device will do the same calulation when the command is received. If the last byte doesn't match it won't respond or send an error code back. It's an error checking thing.
Example for the power on command
The $83,$45 are a constant for every command. The $01 is the power on command. The $C9 comes from adding $83,$45,$01. The problem comes when the sum is greater than one byte. In that case you drop the higher 8 bits and use just the lower 8 bits.
Hope that helps.
If you do something along the lines of
SEND_STRING SomeDev, "($FF+$AA)"
The SEND_STRING call will automatically send the lower byte of the result and ignore the upper.