Technical information

OPTO DIO Reference Opto OUT24
Note when using the INVERTING ULN2804 SINK DRIVERS
the Watch Dog signal is also inverted by these drivers, thus the
RESHI/LO and GOODHI/LO legends are the inverted.
Figure 5-9. Watchdog Output Select.________________________________
FACTORY SET___________
.. PORT A1 Bit 0 Output. Via Pin 34 of 50D, pin 1 of 50IDC.
. . WatchDog Out Signal Output. Via Pin 34 of 50D, pin1 of 50IDC.
.... WatchDog Out Signal Output. Attach flylead for use inside PC
Pin 3 = Watch dog signal NOT OPTICALLY ISOLATED
34 Pin 4 = PC ground NOT OPTICALLY ISOLATED
Opto OUT24 Memory Map.________________________
The Opto OUT24 has 24 dedicated output lines arranged as
3 eight bit read/write registers and one read/write watchdog
enable/strobe register. Thus the Opto OUT24 card occupies 4
consecutive i/o addresses. See Figure 5-10. The output ports are
output only, however the output registers are read/write, writing
to them sets the level of the output lines, reading them provides
a read back of the previously written value. On power up, all the
output lines are reset to zero, low, ie the output drivers are off.
Outputting data to the Port A, B and C registers sets the
external output line either high or low. Inputting from the ports
returns the previously set value. Writes to the watchdog register
gate the signal selected by the BUS jumper onto IRQ line or
RESET line of the PC. Reading the watchdog register refreshes
the timer and postpones timeout for another 50milliseconds.
Page 60 Chapter 5