53A-410 BCD/ 40-BIT BINARY INPUT CARD
• Accepts up to 10 BCD digits (40 bits of binary data) at rates up to 7,000 10-digit transfers per second
• Compatible with high or low true logic
• Data to storage transfer rate of less than a microsecond
The BCD Input Card enables the CDS System to receive discrete outputs from a Unit Under Test or digital data from external instruments, such as parallel output digital voltmeters and counters.
The Card accepts ten BCD digits (40 bits) of TTL data either high or low true 8421 code transferring data to storage on the BCD Input Card in less than a microsecond.
When input is requested from the BCD Input Card by the system controller (calculator or computer), the BCD Input Card transfers the digits from storage via a BCD to ASCII translator, to the system controller The most significant digit will be sent first and the last of the ten digits will be followed by CR/LF (carriage-return, line-feed).
Capacity: 10 BCD digits (40 bits).
Logic: TTL high or low true (switch-selectable). 8421 code.
TTL (S/N 7496, with a 2.2 KOhm pull-up resistor).
Input may be controlled by contact closure of TTL outputs such as BCD outputs from an instrument. With the pull-up resistors, the data source must sink 4.0 milliamperes per data line. The pull-up resistors can be removed, reducing the sink current to 1.6 milliamperes per data line.
Data Transfer Time:
Latched in less than a microsecond for all 40 bits from the user’s instrument to the BCD Input Card.
This is the rate at which data can be input continuously by the system controller (calculator or computer) from the user’s instrument. The BCD Input Card is capable of a data rate of 7,000 ten digit transfers per second. In a typical system, throughput will be limited by the user’s instrument the CDS System communications card, and the system controller.
Data Accept Line (output to data source):
High or low true TTL level (switch-selectable).
Transition to high or low level occurs approximately 2.8 microseconds after data is accepted.
Fan out of 10 TTL loads.
Rise and Fall Time, 25 nanoseconds maximum.
Data Ready Line (input from data source):
High true, low true or ignored (switch-selectable).
Loading, one TTL load.
Minimum Pulse Width, 30 nanoseconds.
Maximum Rise Time, 5 microseconds.
OPT 05, special modification for use with ACX buffer command.