Beijer Electronics MT 223 EN User Manual

Page 28

7.8. Serial Interfaces

RS-232: Interface serves for the data communication. Data will be transfered as ASCII code (American standard code

OF information inter-CHANGE). The RS232 represents a voltage-referred interface, and is thus only for short cable

lengths by approx. 10m - 15m suitably.

RS-485: bus interface operates as RS422 in the opposite clock mode; however only two lines are needed, which are

half duplex. The RS-485 makes connection possible of several transmitters and receivers with the help of a protocol

(up to 32 participants). The ISO standard 8482 plans a maximum cable length of 500 meters. With capacity and/or

absorption-poor, in pairs stranded (twisted pair) cable, can be increased the distance between two terminals: RS485

supports thus cable lengths of up to 1.2 km.

Function: Connection between PC and monitor to configure, control and read status. In the RS232 mode point to

point connection, in the RS485 mode interlacable to 16 monitors. Functions such as status read (firmware, version,

display ID…), control (brightness, backlight, potentiometer…) as well as configure (IP address, subfunctions of the

OSD menu…) are made available. (see chapter programming)

RS232 Mode

RS485 Mode

Note:

In the RS485 mode the two interfaces can be used as (In/Out) that means one cable in the 1st. Com port and one

cable in the 2nd. Com port.

In RS 232 mode only one of the two interfaces can be used (no matter whichone) don’t connect the unused port with

any cable.

The mode (RS232/RS485) as well as an addressing of the monitors are made over DIP switch, see also for this the

chapter “DIP- witches” and “programming”.