User's Manual

PMAC2 User Manual
Using PMAC2 with MACRO Interface 65
USING PMAC2 WITH MACRO INTERFACE
The PMAC2 controller supports the MACRO ring interface to drives and motors. MACRO (Motion and
Control Ring Optical) is a fiber-optic or copper ring network between controllers such as PMAC2, and
drives and I/O modules. Its key features are a very high data rate of 125 Mbits/sec, and a very simple
protocol that makes its use almost transparent to the control software. It can greatly simplify the wiring
of a motion control or I/O system, particularly if the electronic components are distributed about a large
machine.
PMAC2 can support two different protocols in a packet of MACRO information: the Type 0 protocol, and
the Type 1 protocol. Typically, the Type 0 protocol is used by single-node MACRO slave stations such
as the Performance Controls FLX Drive. The Type 1 protocol is usually used by multiple-node MACRO
slave stations such as the Delta Tau Compact MACRO Station. A single PMAC2 can simultaneously
communicate with slave stations using both protocols. In the following sections, note carefully which
protocol is referenced.
Hardware Setup
The PMAC2 Ultralite boards have the full MACRO interface on board. Other PMAC2 boards have the
MACRO ASIC on board, but require the Acc-42P2 board for the actual interface circuitry. Each PMAC2
with MACRO interface has a single ring output and a single ring input. The output on any station in the
ring is connected to the ring input of the next station on the ring.
The connections between stations on the MACRO ring can be made with either fiber optical cable with
SC connectors, or with twisted-pair electrical cables with RJ-45 connectors. PMAC2 Ultralite boards and
Acc-42P2 boards can be purchased with either type of interface, or with both types, which makes it
possible to have an input of one type, and an output of the other type.
Parameter Setup
Several parameters have to be set up for proper operation of the MACRO ring. In addition, because the
MACRO interface uses different registers than the local analog or digital interfaces, the address I-variables
and conversion table entries for servo and commutation setup will contain different values for MACRO.
Ring Configuration
There are several I-variables on a PMAC2 that control the general configuration of the MACRO ring.
I995: MACRO Role/Status
I995 controls PMAC2’s role on the MACRO ring; for example, whether it is a master or a slave. In most
applications, PMAC2 will be a master commanding slave amplifiers and I/O stations across the ring.
These will be the only cases covered here; for other cases, refer to the detailed description of I995 in the
Software Reference.
Each MACRO ring must have one and only one synchronizing master on the ring. If this PMAC2 is to be
the synchronizing master, set I995 to $30. If this PMAC2 is a master on the ring, but not the
synchronizing master, set I995 to $10 or, preferably, $90. A setting of $90 permits this PMAC2’s phase
cycle to stay synchronized to the synchronizing master, by resetting an internal counter on receipt of a
packet specified in I996.
I996: MACRO Node Activation
I996 controls the address configuration of the PMAC2 on the ring. It is a 24-bit value, and should be
thought of as 6 hexadecimal digits each representing 4 bits. The first hex digit specifies PMAC2’s master
number on the ring, with a range of $0 to $F (0 to 15) Unless this PMAC2 is a secondary master on a
multi-master ring, this should be Master #0.