HP 61010A Owner's Manual page 39

: Front Fane! Control Mode
Figure 3*5, Handshake Enabled
RESET * when the handshake is enabled, the reset field,
appears on the screen only after a handshake sequence
has begun. To start the handshake sequence you must
enable the output, enter a value in the output field, and
press {Return] . The reset field will now appear on the
screen to indicate that the Digital Output is waiting for the
external device to accept the data that has been sent.
When the external device responds with an Output Data
Accepted (ODAC) signal, the reset field no longer appears
on the screen. Point to and select the reset field when it
appears on the screen to clear the handshake if an ODAC
signal is not received. You must also clear the handshake
before you enter any new data in the output value field.
Figure 3-6 shows the timing relationship between the
Output Data Available (ODAV) signal from the Digital
Output and the Output Data Accepted (ODAC) signal that
must be provided by the external device.
Manual Instrument Control 3-15