For computer based remote control from a monitoring & control application, the LBRX-1MT provides a framed protocol with start/stop characters and checksum. With the framed protocol, the receiver expects each message to be packed into a frame as described below.
| char # | example | description |
|---|---|---|
| 1 | { | start character, always ' {' |
| 2 | A | device address, always A |
| 3 | l | first character of the message body |
| . | e | message body ... |
| . | v | .. |
| . | l | .. |
| . | = | .. |
| n-1 | ? | last character of the message body |
| n .tc} | end character, always '} ' | |
| n+1 | . | checksum |
Responses of the receiver are packed the same way. The checksum byte is calculated using an algorithm as implemented by the following formula:
This protocol type is known as MOD95- or Miteq protocol . The receiver also packs it's reply in a protocol frame as described above. incomplete frames, checksum errors or address mismatches let the receiver ignore the message. The time between the characters of a message must be less than 5 seconds or the receiver will treat the message as incomplete.
The receiver automatically detects if it gets accessed through the framed protocol and subsequently disables the the terminal / ASCII protocol. This means in particular: After one start character ( {) of the framed protocol has been received, the device switches to framed protocol mode and subsequently ignores every input which is not packed in a valid protocol frame. To return to the terminal / ASCII protocol mode, switch off the receiver and switch it on again.