73A-308 Tektronix Relay and High Voltage Logic Driver Module

The Tektronix / Colorado Data Systems (CDS) 73A-308 Relay and High Voltage Logic Driver Module is a printed circuit board assembly for use in a card cage conforming to the VXIbus Specification. The 73A-308 provides 80 open collector 300 milliamp relay drivers. The 80 programmable lines are organized as ten banks of eight relay drivers.

Each of the ten banks can be independently configured and responses are in ASCII hex notation for ease of programming, and to insure compatibility with the widest range of system controllers.

The outputs can be controlled as individual relay drivers and as banks of relay drivers. Output is controlled by commands, a VXIbus TTL trigger line, or an IEEE-488 Group Execute Trigger.

Relay driver lines can be set inactive (tri-state) or active low under program control. All lines are capable of up to 300mA of sink current per output, with a maximum voltage drop of 500 mV across the output to common. The 80 drivers have built-in transient suppression diode or clamp diodes to eliminate voltage spikes created when relays turn off.

There are two output connectors on the 73A-308, P4 and P5. Each connector has the outputs of 40 drivers, two clamp diode lines, and eight grounds. The clamp diode lines may be jumpered to any of the five blocks of eight outputs (a single UDN-2596A driver chip is a block of eight drivers).

The 73A-308 provides full access to system status information, which is especially helpful during system trouble-shooting, software de-bugging, and operational system checks. At any time, the system controller can read the state of the relay driver outputs and up-to-date error data.