Specifications

2-12
Programming the HP 71612 Series
Handling Coupled Parameters
Figure 2-2 Clock/Data Amplitude and High-Level Relationship with −2V
Termination
The Figures shows the region of valid amplitude and high-level. To move from the point A
to the point B, for example, requires some care. This arises because, if the amplitude is
first moved, followed by the new value of data high-level, then the intermediate state will
be at point C and this would generate an error message.
There are two methods of overcoming this problem:
1. The order of issuing the amplitude and high-level may be used to prevent the bottom
sloping line being crossed. The algorithm would be:
If the new amplitude is greater than the old amplitude, then send the new high-level
first, followed by the new amplitude.
If the new amplitude is smaller than the old amplitude, then send the amplitude first,
followed by the high-level.
2. A dummy move of the high-level to a value between 0V and −2.0 V is followed by the
new value of amplitude, followed by the new value of high-level.