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The TEV-IB0 implements one RS232/422/485 serial port. The port is built around SIPEX SP334 multi-protocol transceiver IC. A small PIC10F200 microcontroller from MICROCHIP is also used. This microcontroller replaces discreet logic that would be needed to control the SP334 in different operating modes. Related datasheets, assembly program for the microcontroller, as well as the schematic diagram for the TEV-IB0 board can be found on Tibbo website.
Two switches are provided on the board for protocol selection. Switch 1 selects between RS232 and RS422/485 signal levels. Switch 2 selects half-duplex or full-duplex mode of operation. Note that these switches only control the operation of the SP334. Serial ports of the EM1000 must be correctly preset for desired communication mode as well.
For your convenience, each TEV-IB0 board is supplied with a TB100 terminal block adaptor.
DB-9M connector pin assignment
Required initialization code in Tibbo BASIC/C application
This section assumes that you are familiar with Tibbo BASIC/C and TIDE software. These are documented in the "TIDE and Tibbo BASIC Manual".
Correct preset of serial ports falls outside the scope of this manual. This section will only remind you that you need to set a correct serial port mode matching the mode selected by the switches of the TEV-IB0. For RS232 or RS422 mode, set ser.interface=PL_SER_SI_FULLDUPLEX. For the RS485 mode set ser.interface=PL_SER_SI_HALFDUPLEX.
Do not forget that all lines of the EM1000 are configured as inputs by default. Any line that should work as an output should be configured as such. This is done through the "I/O" (io.) object. The only exception is the TX line that becomes an output automatically once the serial port is enabled.