ICS ELECTRONICS 4863 Manual page 18

1.6.9 Status Inputs
Two external device status inputs with 33 Kohm pullups to + 5 Vdc. Inputs
sampled at an approximate 1 kHz rate and the states placed in the Operational
1
Register in the 4863/2363's IEEE-488.2 Status Reporting Structure. Status
logic polarity is defined by a configuration command. Input logic levels are
same as the input levels in paragraph 1.6.1.
Status A may be used for output data handshaking. If output handshaking
is enabled, data is only output and the Strobe line pulsed when the Status A
input is true. A false input inhibits data transfer.
Status B may be used as a request for the 4863 to go to the local state. The
4863 will deassert the Remote output in response to a true Status B input if
the unit is not in the GPIB Local Lockout State.
1.6.10 LED Driver Outputs
Five, low true driver outputs for driving remote LEDs. Maximum sink
current is 15 mA at 0.5 Vdc.
1.6.11 Timing Diagrams
Figure 1-1 shows input data handshake timing from setting the EDR input
until the data is placed on the GPIB bus. Figure 1-2 shows output data from
command terminator until data is present on the output lines. Figure 1-3
shows how the Digital I/O lines are configured after a power turn-on or
when the board is reset. The time values are listed in Table 1-2.
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