Delta RMC151 - Manual (Page 76)

RMC70/150 and RMCTools User Manual
The RMC offers homing of quadrature, incremental SSI, and incremental Resolver axes. All are
described in this topic.
How to Home an Axis
This section describes the basic steps for homing a quadrature axis using the Home input
and/or the Z (Index) pulse as the home trigger. The RMC has many options for homing;
for more details, see the rest of this topic.
Note: If you are using the Z pulse, it is important to specify the Z Alignment before homing.
See the Using the Z Trigger section below.
1. Arm the Home
In order to perform homing, the home must first be armed. This means that the RMC
will be looking for the specified trigger to occur, and when it occurs, will set the Actual
Position to the specified position.
To arm the home, issue the Arm Home (50) command. This command has three
parameters:
a. Home Position:
This is the position to which the Actual Position will be set when the specified
trigger occurs.
b. Trigger Type:
This is the trigger that the RMC will wait for. This is either the Home Input
(select rising or falling), or the Z Input, or a combination thereof.
c. Repeat mode:
This specifies whether the homing should occur every time the trigger occurs,
or only once.
When the axis is armed, the Home Armed status bit will be set. This bit can be viewed
in the Axis Status Registers All tab, in the Home section.
2. Move the Axis Until it Homes
Move the axis so that it reaches the specified trigger, such as the Home input or Z
pulse. To move the axis, use any motion command you wish. Typically, a Move
Velocity works well. When the specified trigger occurs, the Actual Position will be set to
the specified position. The Target and Command Positions will be adjusted by the
same amount that the Actual Position was adjusted, and the motion will therefore not
be affected.
When the home has occurred, the Home Latched status bit will be set and the Home
Armed status bit will be set. If the Repeat Mode parameter was set to Repeat, both
the Home Latched and the Home Armed status bits will remain set. These status bits
can be used in a user program to check that the home has occurred. The Home Input
status bit also shows the current state of the home input.
When the home has occurred, issue a command to stop the axis or move it to some
desired location.
Quadrature Homing Details
This section gives more detail on homing a quadrature axis.
Trigger Types
The following trigger types are available on quadrature axes.
#
Trigger
Type Description
Valid for
RMC70 RMC150
0 H Rising Trigger a Home on the rising edge of the Home Input. QAx, Q1 Quad, UI/O
1 H Falling Trigger a Home on the falling edge of the Home Input. QAx, Q1 Quad, UI/O
56 Delta Computer Systems, Inc.