Delta RMC151 - Manual (Page 79)

3 Controller Features
Using the Home Input for SSI and Resolver Axes (Trigger Types 0 - 1)
The Home input for SSI and Resolver axes is defined as follows:
Feedback Type Home Input
Incremental SSI Defined by the SSI Home Source parameter
(RMC70 only).
Incremental Resolver No Home input is available on Resolver inputs.
When the home is armed and the Home Input trigger occurs, the exact counts at the time
the trigger occurred are latched. This position is used as the physical home position. For
SSI and Resolver axes, the counts are only read once per control loop, so the time to
latch can be up to one control loop (500μs to 4000μs).
Using the Z input for SSI and Resolver Axes (Trigger Types 2 - 4)
The Z pulse for SSI and Resolver axes is defined as follows:
Feedback Type Home Input
Incremental SSI The zero Raw Counts position of the encoder.
Incremental Resolver The zero Raw Counts position of the resolver.
For incremental SSI and resolver inputs, the Index pulse is given by the point when the
Raw Counts cross zero (0). This will trigger a home in the same way that the index (Z)
input will. However, there is no Learn Z Alignment parameter and no need to issue the
Learn Z command.
Notice that for high-turn-count multi-turn SSI encoders, the Raw Counts may cross zero
very infrequently. Therefore, homing with trigger types 2-4 on an SSI encoder is typically
only useful for single-turn encoders.
Using the Absolute Home Latch (Trigger Types 5 - 7)
When the home is armed and the specified home trigger occurs, the Actual Position for
the SSI axis is adjusted such that the Actual Position at zero Raw Counts of the SSI or
Resolver will be set to the requested Home Position as specified by the Arm Home (50)
command.
Notice that trigger type 7 will perform the homing immediately when the command is
issued. Trigger type 7 is supported by the SSI and Resolver, but trigger types 5 and 6 are
supported only by the SSI.
3.2.6. Physical Limit Inputs
Each RMC axis allows for optional physical limit inputs to specify the boundaries in which the
axis is allowed to operate. Each axis can have two physical limit inputs: Positive Limit Input
and Negative Limit Input. Typically, these inputs are wired to limit switches.
The physical limit inputs differ from the Travel Limits, which limit the range of travel of an axis
based on the feedback (position, pressure, etc.). The Travel Limits are required to be set on
an axis; physical limit inputs are optional.
Setup
Use the Positive Limit Input and Negative Limit Input parameters to specify the inputs to
be used for the physical limit inputs. The following options are possible:
Option Description
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