Hybrid T-Bar Relays are available for logic control.
There are three schematic diagrams with three different drivers.

D (Driver Current Supplied)
Designed to operate from a low current 24 volt source. 
Supplying +24 volts will operate the relay.

Q (TTL or SW)
Designed to operate from a TTL Drive or Switch. A "Logic 1" or a voltage between +2.4 volts and + 5.5 volts will operate the relay. A "Logic O" or any voltage less than 0.8V will deactivate the circuit. It can also be operated from switch or contact closure. An Open Contact or switch activated the circuit. A closure deactivates the circuit.

Ordering Information
Example of part #: 7901-12C-28*
T-Bar Series (7901)
Number of Contacts (12)
Contact Form (C)
Coil Voltage (28)
* All other options see 801/901 Series

* 24 and 28 volt DC systems standard.

* Available in 12, 24, 36, 48, 52 poles from C, double throw, transfer switching.

* Protected against normal ambient dust conditions.

* T-Bar Connectors are hightly recommended.

Z (Inverted TTL)
Designed to operate from inverted TTL circuits. A "Logic O" activates the circuit. A "Logic 1" or open circuit (open collector deactivates the circuit.)