User manual
DBK25  8-Channel Relay Output Card 
Overview …… 1 
Hardware Setup …… 2 
Card Connection …… 2 
Card Configuration …… 2 
DaqBook and DaqBoard and DaqBoard/2000 Connection …… 4 
DaqBook and DaqBoard Configuration …… 4 
Software Setup …… 4 
DBK25 – Specifications …… 4 
Reference Notes: 
o  Chapter 2 includes pinouts for P1, P2, P3, and P4. Refer to pinouts applicable to your 
system, as needed. 
o  In regard to calculating system power requirements, refer to DBK Basics located near 
the front of this manual. 
o  DBK25 users may be interested in the DBK208 module. DBK208 is a Carrier Board for Opto-22 
Compatible Solid-State-Relays. Refer to the DBK208 section for additional information. 
Overview 
DBK25 provides 8 normally-open relay contacts for isolated switching of AC or DC loads or signals via 
the LogBook’s P2 digital port or via the Daq device’s or adapter’s P2 digital port. The P2 port operating in 
the expanded-I/O mode can address up to 32 DBK25s (256 relays max). The DigiBook/72 with 3 P2 ports 
can address 96 DBK25s for up to 768 relay contacts. The relays are 2-coil sub-miniature latching relays 
and do not require continuous current to stay closed.  Such bi-stable relays can act as an 8-bit non-volatile 
write-only memory byte. 
The steady-state power drain of the DBK25 is very low, less than 1 mA at 5 VDC. It is practical, even 
operating on a battery, to have hundreds of relay contacts. The stored-energy operation of the DBK25 does 
limit the practical on/off speed (or the ability to generate 50% duty cycles) to about 10 Hz. The relay's 
operating time is less than 15 ms. 
DBK Option Cards and Modules  879795  DBK25, pg. 1 










