Hello

We got this device with the intent of being able to monitor and shut down 3 different motors based on temperature.

My concern with the unit was that it only had one relay contact and I have three distinct motors. The distributor assured me that the digital outputs could control Solid State Relays and effect the switching.

I've got it on my desk and I'm issuing state changes to digital channels and getting 0mv at state '0' and around 3.3mv at state '1'. This is not within the specs of typical 0 and 5v TTL; What am I missing here?

Good morning rbooks,

The DT80 is CMOS level not TTL.
Which digitals are you using?

If you are using digital i/o/ 1 to 4 then I would recommend you use an external relay as per DO1 on page 318 of the DT80 user manual (UM-0085-B7)
If you are using digital i/o/ 5 to 8 then I would recommend you use an external relay as per D04 on page 319 of the DT80 user manual (UM-0085-B7)

Cheers,
Roger

I would like to add that if your device being controlled by the dataTaker was TTL compatible then it would register a 1 for a voltage of 3V which is what should be visible on the output of the digital channels 1-4 when high.

From WikiPedia about TTL Voltage levels:

A TTL input signal is defined as "low" when between 0 V and 0.8 V with respect to the ground terminal, and "high" when between 2.2 V and 5 V[19] (precise logic levels vary slightly between sub-types and by temperature). TTL outputs are typically restricted to narrower limits of between 0 V and 0.4 V for a "low" and between 2.6 V and 5 V for a "high", providing 0.4V of noise immunity.