NEC NP-PX700W Command Manual page 6

[ GT/LT80/MT/NP1000/VT (except
VT70/VT80/VT90)/NP3150/NP905/NP600/NP4000/NP3250/NP610/NP2200/NP216/M300/P420/U300/V300 ]
The PC CONTROL connector is a D-SUB 9-pin connector.
1
2 To TxD of PC
3 To RxD of PC
4
5 To GND of PC
6
7 To CTS of PC
8 To RTS of PC
9
====================================================================
4. Communication Frame
----------------------------------------------------------------------
On the LT/MT/SX/GT series projectors communication is done in a frame
composed of header, data, and checksum.
The frame sent from the controller to the projector is referred to as
a command, and the one sent from the projector to the command as an
reply is referred to as a response.
The response has two types; Acknowledge (hereafter referred to as ACK)
that recognizes a command and Negative Acknowledge (hereafter referred
to as NAK) that fails to recognize a command.
+--------------+ Command
| |-------------->|
| Controller |
| |<--------------|
+--------------+ Response +--------------+
(ACK or NAK)
4-1. Frame Format
**********************************************************************
One frame comprises a header, a data portion, and a checksum.
Frame Format:
+-------------------------------+----------------------+--------+
| Header portion
| | (Max. 4095 Bytes) |
+-----+-----+-----+-------+-----+-----+--
| 1 | 2 | 3 | 4 | 5 | 6 |
+-----+-----+-----+---+---+-----+-----+--
| 8 | 8 | 8 | 4 | 12 | 8 |
| Bit | Bit | Bit |Bit| Bit | Bit |
+-----+-----+-----+---+---------+-----+-- ~ --+-------+--------+
| | | | |
| | | | +------------- Data length
| | | +-------------------- Model code
| | +------------------------- Projector ID
| +------------------------------- ID2
+------------------------------------- ID1
* ID1: (8 Bit)
+--------------+
|
| Projector |
|
| Data portion |Checksum|
--+-------+--------+
~ | n | m |
--+-------+--------+
~ | 8 | 8 |
~ | Bit | Bit |
|