CD22 Tailgate Interface Specification
The CD22 is a very compact, low cost tailgate interface device for the IBM 468x and IBM 469x Cash Registers. The CD22 emulates the RS232 logical interface supported by the IBM Feature C or D cards, and connects directly to an appropriate IBM ECR tailgate port, eliminating the need for the expensive IBM ECR Feature C or D cards or other serial port upgrades on the ECR.
The CD22 allows an RS232 serial port configured device to be connected to an IBM Cash Register via tailgate ports 9 or 4. If the power requirements of the RS232 serial port attached device are 12vdc 1A or less, the attached device may be able to use power pin 9 on the CD22 RS232 DB9 port and indirectly use power supplied from the Cash Register.
NOTE: the unregulated 12vdc, max 1A, delivered from the CD22 to the attached device is not fused.
The CD22 allows new and legacy RS232 serial port configured devices to easily connect to an IBM Cash Register, without adding an IBM Feature C or D card to the Cash Register. The CD22 has 1 port, an RS232 DB9 port to allow the connection of a POS or related device, and a cable with a SDL connector that plugs into the IBM Cash Register.
CD22 RS232 DB9 Female port:
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NOTE 1: regarding Pin 9, the CD22 only uses approx. 200 mA of the power made available from the IBM 468x or 469x cash register to drive the CD22, and passes on the remaining power to the attached RS232 serial port device as unregulated 12 vdc. The maximum power available to the attached device will be approx. 1A depending on the IBM ECR model and combined loading on ports 4 and 9. CD22 Tailgate Communications connector: The CD22 has a built-in 3m long cable with a Shielded Data Link (SDL) connector. This 4 pin connector simply plugs onto tailgate ports 4 or 9 on the IBM Cash Register. This SDL connector uses "A" keying. |
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Data Transfer and Device Address:
The CD22 will interface to the POS device at 300 bits per second to 38.4k bps. The speed, data parity and number of bits are all configured using an initialization message from the IBM Cash Register.
The CD22 uses IBM's "tailgate" protocol. The CD22 uses timing gaps in the data stream received on the serial port to build packets to be sent to the cash register. Each time there is a 10ms gap, or the 256-byte receive buffer is filled, the collected data is sent to the cash register. Data Packets received from the cash register are sent out the serial port immediately.
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The CD22 will wait for a 10ms delay in the data stream from the POS device or the 256- byte buffer is filled before sending the message to the IBM Cash Register. The CD22 will interface to the IBM Cash Register at a rate of up to 187.5K bps. The CD22 uses a half duplex asynchronous SDLC like protocol, IBM calls it the "tailgate" protocol. The Device Address can be either 64,65,68 or 69 and is established by placing 0,1 or 2 jumpers on 2 headers inside the CD22. |
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The CD22 will require 12vdc approx. 200mA; this power is obtained from the IBM Cash Register via the SDL connector. The remaining power available (max. 12vdc 1A) is provided to the POS Device via Pin 9 on the CD22 RS232 DB9 port (unregulated, not fused).
Temperature:
Operating: 0C to 70C (32F to 158F)
Storage: -40C to 85C (-40F to 185F)
Physical Specifications:
