Function: Wiegand and clock/data reader port plus one open collector output.

Form factor: M1S

Category: Input/output module

Special needs: [SER]

Power requirements: 5V/TBDmA

Mates with: #19, #20, #21 (limited use)


 

Details:

Our programmable devices (such as TPP2 and TPP3) have the unique ability to process input from card readers with clock/data or Wiegand interface. This is achieved through the ser. object running in the clock/data or Wiegand mode. Tibbit #08 implements necessary hardware.

In order to be able to process card reader output, this Tibbit has to be connected to the RX and CTS lines of the CPU's UART (see [SER]).

When connecting a clock/data reader, wire the clock line to IO1, and the data line to IO2. Set the CONTROL line to LOW -- this selects the clock/data mode for the Tibbit's hardware.

When connecting a Wiegand reader, wire the W0 line to IO1, W1 line -- to IO2. Set the CONTROL line to HIGH to select the Wiegand mode.

In both cases, the IO3 line must be connected to the external power source. Most card readers with clock/data and Wiegand interfaces have open collector outputs. Such outputs require pull-up resistors on the receiving end. On this Tibbit, the role of pull-up resistors is played by opto-LEDs and resistors connected in series.

The exact voltage of the power source depends on the reader. Very often it is the supply voltage for the reader itself (typically, +12V). In this case just split the reader power line and connect the same power to IO3. Some readers require 12V power and pull-up resistors to 5V. This means IO3 will need to receive +5V.

This Tibbit also has a standalone open collector output controlled through LINE D. Set LINE D LOW to open the transistor. When left unconnected, the line defaults to HIGH (hence, the transistor is closed).

Combine this Tibbit with terminal block devices -- #20 (nine terminal blocks) or #21 (four terminal blocks). Note that #21 doesn't provide the ground line, and using this Tibbit requires the ground line between the reader and your system. Hence, if you use Tibbit #21 you will need to "steal" the ground somewhere else.

 

Check out the Tibbit #11 (four open collector outputs) if you are looking to emulate clock/data or Wiegand reader output (that is, of you want to turn your device into a reader that outputs data).      

LEDs

There are four LEDs: two red and two green. Red LEDs are connected to the CONTROL and OC line. Green LEDs are connected to W0&1 and W1 lines. All LEDs are buffered (with logic gates) and light up for the LOW state of control lines.