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Geo MACRO Drive User and Reference Manual

Setting Up Secondary Encoders

SETTING UP SECONDARY ENCODERS

Geo Drives have also secondary encoder inputs that can be used for dual feedback. The input signals need
to be digital quadrature encoders. Single Axis drives have one secondary encoder and dual axis drives
have two secondary encoders.

Secondary encoders so as to be enabled require a motor node. So the user needs to “burn” a motor
channel/node so he can read the encoder feedback. The motors need to be activated Ixx00 equal to one,
and activate the MACRO motor nodes I6841/I6891/I6941/I6991, and set MS<node>, I996 enabled.

Note:

The Secondary Encoders of a Geo MACRO drive can not be assigned to nodes before the

primary nodes of that drive. For example if you have for your primary encoders node 4

(channel#1) and node 5 (channel#2), then the secondary encoders can be in any free motor

node after that 8/9/12/13 ( MACRO IC0) , 16/17/20/21/24/25/28/29 (MACRO IC1),

32/33/36/3/40/41/44/45 (MACRO IC2), 48/49/52/53/56/57/60/61 (MACRO IC3), and

cannot be assigned as node 1 or 2 or any occupied by another motor node.

For the Secondary encoders at the Geo MACRO drives the MI variables are a little different than the
primary encoder channels. By setting MI910 equal to 0 (default) the encoder decode is x4 (cts.) or it can
be set equal to 1 for an encoder decode x1 (cts.)

The user can only reverse the direction by setting the MS<node>,MI911 equal to 0 for Clockwise(CW) or
equal to 1 for CounterClockWise (CCW). Make sure when you change the direction decode that the
output sense direction also follows, else runaway can occur.

For capturing the user needs first to select which input to use, Home Flag or Index channel. MS<node>,
MI915 . If the user wants to capture on the Index channel (only) then MI915 has to be set equal to $C0. If
the user wants to capture on the Home Flag then MI915 needs to be set equal to $6000. For capturing to
both inputs, Home Flag and Index Input, MI915 needs to be set equal to $40C0. Depending on the input
that the user chose, MI912 or MI913 need to be set respectively. For Capturing at the Index input (C
channel) MS<node>,MI912 can be set equal to 0 for capturing at the rising edge, or equal to 1 for
capturing at the falling edge (edge trigger not level trigger). Default the value is equal to 0. The trigger
would be armed as soon as the position capture register is read.

If the user wants to capture at the Home Flag (HMFL) then MS<node>, MI913 has to be set equal to 0 for
capturing on the rising edge, or equal to 1 for capturing on the falling edge (edge trigger not level trigger).

Using the secondary encoder requires enabling an additional motor (not I/O) node, in both the Geo
MACRO drive and the Turbo PMAC to transfer the data back to the Turbo PMAC.

If the user wants to use only one primary encoder and one secondary encoder without “burning” extra
motor nodes, it is possible to disable the second primary encoder of the drive (check “MS<node>,MI100”
variable), and enable the appropriate motor nodes. For example, if the user wants to setup a single axis
Geo MACRO (Station=1) with one quadrature primary encoder and one secondary encoder, he would
have to enable two motor nodes. (no I/O nodes are being set for this example)

MS0,MI996=$FC003

; Enable motor nodes 0 and 1

MS0,MI100=1

; Disable second primary channel

MS0,MI101=0 or 1

; Set up the primary encoder channel for quadrature feedback

MSSAVE0

; All changes to take effect

MS$$$0 or power cycle

I100=1

; Activates axis #1 position

I200=1