This 8ASTU PCB connects 8 analog extensions. to your DS2000 cabinet.These can include single line telephones, fax machines, modems or Voice Mail ports. Just like the 16DSTU PCB, the 8ASTU has a Mode Switch, a status LED indicating proper PCB operation, and a port activity LED to indicate traffic on the PCB.
In Universal Slot systems, you can install 8ASTU PCBs in any universal slot except the first.
In Fixed Slot systems, you can only install an 8ASTU in the second universal slot.
"B" Version required for Caller Identification to Single Line Telephone