Measurement Computing Digital488 - Manual (Page 23)

Section 2 Getting Started
2.7
2.3.3.2 Data Strobe (Pin 42)
The Data Strobe output is pulse for approximately 50
microseconds after new data is output on the I/O port. The Data
Strobe line is normally active high but may be programmed active
low by the Invert command (I4). The Handshake command (H1)
can pulse the Data Strobe line, independent of an I/O operations.
Timing Diagram for Strobe Output
DATA VALID
15 µS min
50 µS typ†
† 15 µS typ in F5 Format
DATA
STROBE
2.3.3.3 External Data Ready [EDR] (Pin 46)
The External Data Ready [EDR] line is an edge sensitive
input which is used to latch input data. It is used in conjunction with
the Data Ready command (R1). The EDR signal must be at least 1
microsecond wide and must have a rise and fall time of less than one
microsecond. The EDR line is normally rising-edge sensitive but can
be programmed with the Invert command (I32) to be falling-edge
sensitive. Refer to the following diagram for timing relationships.
When using the EDR line with the R1 command, data is not
read when the Digital488 is addressed to talk as with R0. The
Digital488 will only output data when the EDR line transitions.
EDR is not functional in the high speed binary (F5) format.