Princeton 4300 User Manual

PI-SCX System Manual

Version 2.E



Shielded Metalized hood (Radio Shack part no 276-1536A).



BNC connector(s) type UG-88 Male BNC connector (Radio Shack part no 278-103).

Example

Suppose you needed to build a cable to monitor the line TTL OUT 1. One approach

would be to build a cable assembly as described in the following paragraphs. This

procedure could easily be adapted to other situations.
1. Begin with a 25-pin female type D-subminiature solder type connector (Radio Shack

part no 276-1548B). This connector has 25 solder points open on the back.

2. Referring to Table 5, note that pin 8 = GND and pin 9 = TTL OUT 1.
3. Using coaxial cable type RG/58U (6 feet length), strip out the end and solder the

outer sheath to pin 8 (GND) and the inner line to pin 9 (TTL OUT 1). Then apply

shielding to the lines to insulate them.

4. Mount the connector in a Shielded Metalized hood (Radio Shack part no

276-1536A).

5. Build up the cable (you can use electrical tape) to where the strain relief clamp holds.
6. Connect a BNC connector (UG-88 Male BNC connector) to the free end of the cable

following the instructions supplied by Radio Shack on the box (Radio Shack part no

278-103).

7. To use this cable, connect the DB-25 to the TTL In/Out connector on the back of the

ST-133.

8. To check the cable, start WinView/32 and open the TTL Diagnostics screen (located

in WinView under

Hardware Setup|Diagnostics). Click the Write radio button.

Then click the

Output Line 1 box. Next click the OK button to actually set TTL

OUT 1 high. Once you set the voltage, it stays until you send a new command.

9. Measure the voltage at the BNC connector with a standard voltmeter (red on the

central pin, black on the surrounding shielding). Before clicking

OK at the TTL

Diagnostics screen you should read 0 V. After clicking

OK you should read +5 V.

Note that adding a second length of coaxial cable and another BNC connector would be

straightforward. However, as you increase the number of lines to be monitored, it

becomes more convenient to consider using a multiple conductor shielded cable rather

than individual coaxial cables.