MVS-8100D Hardware Description 2
34 Cognex MVS-8100D and CDC Cameras Hardware Manual
Figure 14 shows the bidirectional parallel I/O circuit for each TTL_BI_n line.
Figure 14. Bidirectional parallel I/O circuit
Notes on the parallel I/O circuitry:
• The minimum allowable Vcc is 4.75 V.
•If direction is high, the circuit is an input; if direction is low, an output.
• In output mode, the 74ABT125 drives the TTL_BI_n signal high and low. That is, it
is not an open-collector output.
When a bidirectional line is configured as an output line, the output current for logic high
voltage (VOH) for each TTL line is 32 mA, and for logic low voltage (VOL) is 64 mA.
When a bidirectional line is configured as an input line, it is the responsibility of the
application to drive the circuit both high and low. Do not let the circuit float to signal low.
3 TTL_BI_5 8 TTL_BI_4 13 TTL_BI_3
4 TTL_BI_2 9 TTL_BI_1 14 TTL_BI_9
5 TTL_BI_12 10 TTL_BI_11 15 TTL GND
Pin Signal Name Pin Signal Name Pin Signal Name
Table 18. Pinout of parallel I/O connector on MVS-8100D2 and MVS-8100D3
74ABT125
TTL_BI_n
74LVC126
Direction
Vcc (5V)
200 mA
