The high density 68 pin SCSI II/III connector is being used for purposes other than SCSI interfaces because of board and front panel space limitations. For example in the PMC/XMC environment SCSI connectors provide an excellent size and pin count for the front panel space allowed. The SCSI connector while dense, is not easy to connect to with wiring intended to go to multiple locations.
HDEterm68 terminal provides an easy way to get from a high density SCSI connector to discrete wires. For example with the PMC-Parallel-TTL design a standard SCSI cable can be used to connect the PMC to HDEterm68, and then to the system wiring via the screw terminal strips provided. HDEterm68 provides a space efficient, low cost method of interconnecting the control electronics to the rest of the sensors, IO, machinery etc.
HDEterm68 comes with two SCSI II/III compatible connectors. One connector could be used for a termination plug or for a second SCSI cable. The screw terminals could then be used as testpoints. The SCSI connectors are connected to the screw terminals and to each other 1:1. The "in" SCSI connector is connected to the screw terminals and then to the "out" connector. The SCSI connectors can be right angle "-H" or verticle "V" or mixed "-M".
The SCSI connectors and terminal block are interconnected with differentially routed matched length traces. With Revision F of the standard board, and Revision A of the -ENG version, Internal ground/power planes are used to reference the traces to provide 100 ohm differential impedance.
On the -ENG model several sets of resistors allow isolation and termination options. For example the two SCSI connectors can be isolated and the header strips used to reconnect in a custom manner. In addition two header strips are available to allow for loop-back and custom terminations. The first header "TP1" is tied via 0402 resistors to P1 [primary SCSI connector]. The resistors are optionally installed to allow direct connection or terminated connection, resistive, capacitative etc. to the header strip. The second header strip "TP2" is tied to the terminal block. The isolation resistors between P1 and the terminal block can be left uninstalled and the path through the TP1 header used to allow for wiring options and other added circuitry. Please note that TP1 and TP2 are installed by customer request. Additional features include: power entry and distribution posts, oscillator, regulator, LED and transceiver positions. Please send us your specifications. We will assign a modified part number and build a custom terminal block for you.
The standard configuration uses a minimized PCB that interconnects the two SCSI connectors, terminal strip and screw terminal block. The routing is matched from P1 to the terminal strip and from teh terminal strip to P2.
2 - SCSI II/III compatible with cable locks
SCSI connectors can be vertical, horizontal or mixed. Please specify -V, -H or -M
2 row by 34 terminal strip with side entry wires and top screw lock. Rows are offset for ease of access.
Available with plastic and DIN rails -P or as shown for bench top operation.
Also available without the plastic and terminal block for a low cost loop-back fixture.
With plastic: 10.5oz
Without plastic: 6.5oz