Delta Tau PMAC Pack, Hardware Reference Manual

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PMAC-Pack
26 Getting Started
Figure 2-6. Flag Connection Pinouts
Encoder Variable Setup
Several I-variables are linked to the encoder inputs, regardless of which motor the encoder is assigned to.
These control how the encoder signal is interpreted. They are numbered in the 900s: I900-I904 belong to
Encoder 1, I905-I909 belong to Encoder 2, and so on, to I975-I979 belonging to Encoder 16. Initially we
will only concern ourselves with the first encoder’s I-variable.
I900, I905, I910, Etc.
These control the decoding of the encoder signal into counts. Quadrature x1, x2, and x4, plus pulse and
direction decode, are all possible. PMAC is shipped with counterclockwise x4 decode set up (I900, I905,
... = 7). Check this value for Encoder 1 (I900), and change it to 7 if it is different.
I901, I906, I911, Etc. Encoder Digital Filter Disable
These I-variables control whether the digital delay filter for noise spike elimination is turned on. PMAC is
shipped with the filters on (I901, I906, ... = 0).
I902, I907, I912, Etc. Encoder Position Capture Control
These I-variables control which transitions of which associated encoder signals trigger a position capture
for that encoder. This must be used for homing moves; it can also be used for other purposes. It specifies
an edge of the encoder third channel, the edge of one of the encoder flags, or the edge of a logically
combined signal from both. If it uses a flag, you must also set the next variable. The default value for this
variable is 1, specifying the rising edge of the third channel.
I903, I908, I913, Etc. Encoder Flag Select Control.
Caution:
The +LIM on the PMAC-Lite board is actually wired to the NEGLIM terminal of
the PMAC-Pack and the -LIM on the PMAC-Lite board is wired to the POSLIM
terminal of the PMAC-Pack.
These control which of the encoder flags is used to trigger a position capture if the previous I-variable has
specified that a flag is to be used. Usually this is set to 0 to specify the home flag (HMFLn).