All test points must be wired as 4-wire points. You must use the Signature AV4W-64 adapter. This adapter has 2 VME connectors on it. You must pair A1 with C1, A2 with C2, and so on, for each 4-wire connection on the adapter. As you build your fixture keep in mind that you cannot skip over any points in the adapter. The test points used must be contiguous.
Signature 1100H+, 1100R+, and Touch 1 Testers:
These testers are more flexible in the 4-wire mode than the 1000H+. These three testers let you use Signature Adapters in any combination you choose and you can mix 2-wire and 4-wire points in the same assembly. This means you can use 4-wire test points only where you wish to.
Keep in mind that you still must 'pair points' using one type "A" and one type "B" test point for each 4-wire pair. You can be sure of using one of each type point for each 4-wire pair by:
- Using an A1KM-64 adapter and pairing A1 with C1, A2 with C2, and so on (note: if you use this approach, the fixturing will be compatible with CH+ testers also).
- Using the 'AHED Family' of adapters where pin 1 is paired with pin 2, Pin 3 with pin 4, and so on.
- Using IDC ribbon cable for all terminations by using two identical double-high AHED adapters (i.e. (2) AHED-64's). Pair wires between the 2 adapters offset by 2 pin positions: J1-1 to J2 pin 3, J1-2 to J2 pin 4... This can be done by offsetting ribbon cable in the connector before crimping. An IDC connector crimped between the two ends of this cable forms a 4-wire connection. If you don't want to waste the first 2 pins on J2, then take the last 2 pins from J1 and connect them in sequence to the first 2 pins on J2.
- Using the help screen of the Touch 1 and follow the 4-wire constraints.
easy-wire CR Tester:
You can mix 2-wire and 4-wire points in the same assembly on this tester also. Presently, 4-wire measurements cannot be made using "easy-wire adapters" that plug into the easy-wire transition boards.
Note: If you use a ribbon cable with 64 points, you can pair pin 1 with pin 33, pin 2 with pin 34, and so on.
You can also mix 2-wire and 4-wire points in the same assembly with this model tester. Pair point A1 with Point B1, point A2 with B2 and so on.
Note: Use your test probe to identify the test points.