Hatteland Display 20 inch - HM 20T07 CMD - Manual (Page 50)

50 Communication Interface
IND100084-8
Serial Communication (SCOM) Interface
HATTELAND® SCOM Control Interface
This document defines the electrical signals, connectorization, serial data format, and communication protocol of the
Serial Communication Control Interface. The purpose of this interface is to provide means for a computer application
to mainly remote control the LCD backlight.
Interface configuration
The serial interface can have different configurations, selected by several switches as shown in the illustration on the
next page.
Brightness Control Operation
The backlight brightness at the unit can be controlled in two modes. A serial interface is used to command the level of
backlight brightness and to select mode.
1) Using the local manual brightness control, an operator is only able to adjust brightness to levels lower than the set
maximum, including dimming the backlight to extinction.
2) Brightness is independent of local manual brightness control, set by remote control only.
Electrical Interface
Electrical signals shall conform to RS-232. Only Receive Data, Transmit Data, and Signal Ground are used. Hardware
handshake is only supported by loopback handshake for RS-232.