Hardware

Serial connection box

It is a connection box for RS-232 serial port for monitoring RXD/TXD lines. Its operation is very simple: The data of the line selected with Sw1 can be observed on the computer connected to the Out A port when inserted into the serial line. The LEDs show the current logic level of the lines. With Sw2, the RXD and TXD lines of the Out B port can be replaced according to the needs of the connected device.

The device can be attached to a DIN rail with the help of the fastener mounted on the bottom.

Schematic

The schematic can be found in the attached materials. (OrCAD/SDT III v3.21 [1989] format and PostScript format.)

Cables

The cables connected to the PC and the Out B port are straight modem cables. The cable connected to the Out A port is a null-modem cable. Only RXD, TXD and GND are soldered in each cable.

How to use?

The control computer must be connected to the PC port, the monitoring computer must be connected to the Out A port, and the device must be connected to the Out B port. ModBUS/ASCII traffic can also be monitored with a simple serial terminal (e.g. Telix, Minicom), but it is more convenient to use a special program for this (e.g. CleverTerm).

Download

name version type note
Schematic drawing   zip OrCAD/SDT III v3.21 (1989)
 Hackster Project page on Hackster.io
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