NEC LCD3215 External Control Guide - Page 3

4thbyte) Source: Source equipment ID. (Sender) Specify a sender address. The controller must be '0'(30h). 5thbyte) Message Type: (Case sensitive.) Refer to section 4.2 "Message block format" for more details. ASCII 'A' (41h): Command ASCII 'B' (42h): Command reply. ASCII 'C' (43h): Get current parameter from a monitor. ASCII 'D' (44h): "Get parameter" reply. ASCII 'E' (45h): Set parameter. ASCII 'F' (46h): "Set parameter" reply. 6th -7th bytes) Message Length: Specify the length of the message (that follows the header) from STX to ETX. This length includes STX and ETX. The byte data must be encoded to ASCII characters. Ex.) The byte data 3Ah must be encoded to ASCII characters '3' and 'A' (33h and 41h). The byte data 0Bh must be encoded to ASCII characters '0' and 'B' (30h and 42h). 4.2 Message block format Header Message Check code Delimiter "Message block format" is allied to the "Message Type" in the "Header". Refer to the section 6 "Message format" for more detail. 1 Get current parameter The controller sends this message when you want to get the status of the monitor. For the status that you want to get, specify the "OP code page" and "OP code", refer to "Appendix A. Operation code table". "Message format" of the "Get current parameter" is as follows, STX OP code page OP code ETX Hi Lo Hi Lo  Refer to section 5.1 "Get current parameter from a monitor." for more details. 2 Get Parameter reply The monitor will reply with the status of the requested item specified by the controller in the "Get parameter message". "Message format" of the "Get parameter reply" is as follows, STX Result OP code page OP code Type Max value Current Value ETX Hi Lo Hi Lo Hi Lo Hi Lo MSB LSB MSB LSB  Refer to section 5.2 "Get parameter reply" for more details. (3/37)