Delta Tau: Programmable Multi-Axis Controller (MINI-PMAC)

The Mini-PMAC is an inexpensive, compact 2-axis version of the PMAC(1) family.

It can be used in a PC ISA slot as a half-sized board (230mm, 9” long), or it can be used standalone, with serial communications for setup and/or application control.

Programs for the Mini-PMAC, both motion and PLC, are 100% compatible with other versions of PMAC. However, there are several features unique to the Mini-PMAC:

1. There are only two output digital-to-analog converters: DAC1 and DAC2 (DAC3 and DAC4 do not exist). Both have differential outputs. The two analog outputs on the Mini-PMAC can be used as velocity or torque commands for separate axes, or as phase current commands for a single axis commutated by the card. However, there are 4 incremental encoder interfaces that can be used for feedback or master positions. Two of these may alternately be used to process analog voltages through optional on-board V/F converters.

2. There is no JPAN control panel port. There are no digital inputs dedicated to the functions of this port on other PMACs. To obtain equivalent functions, general-purpose inputs would have to be used along with a PLC program reading these inputs. Handwheel encoder(s) may be brought in through the JMACH port. WIPER input(s) may be brought in through the JAUX port if option 15 is purchased.

3. The memory mapping of the general-purpose digital I/O is different from other versions of the PMAC. Different M-variable definitions are required for these I/Os on the Mini-PMAC (see below).

4. There is no bus interrupt capability. There is no programmable interrupt controller (PIC) on board. Therefore, it is not possible to read interrupt status registers over the bus in polled format.

5. The serial port is RS-232 only. There is no on-board or optional capability to use RS-422 format. There is no daisy chaining capability for a Mini-PMAC with other PMACs of any type on a single serial line.

6. Dual-ported RAM (Option 2M) is an on-board option that must be factory-installed. The Mini PMAC cannot use the separate Option 2 DPRAM board.

7. The JTHW multiplexer port outputs are not as powerful as on other PMACs. There should be no more than 1 meter (3 ft.) of cable to any device on the port, instead of the 3 meters (10 ft.) on other PMACs. Anything longer should use the ACC-35A driver board.

8. There are no jumpers to control the open-circuit voltage of the complementary inputs. Instead, there are reversible socketed SIP resistor packs. At the factory, these are configured to tie the complementary lines to 2.5V. Reversed, they will tie the complementary lines to 5V.

9. There is no JXIO connector to provide clock signals to mating connectors on ACC-24P or ACC-8D Option 8 boards. If either of these boards is used with the Mini-PMAC, a custom cable should be made to connect the DCLK signal on the Mini-PMAC J7 port to both the DCLK and SCLK inputs on the ACC-24P JXIO port, or the SCLK input on the ACC-8D Option 8 JXIO port.

10. The HMFLn, PLIMn, and MLIMn flag inputs on the Mini-PMAC can accept signals from both sourcing and sinking drivers. If the A+15V on JMACH is used to supply the flag isolators through E89 and E90, only sinking drivers can be used. But, if pin 13 on J8 (JAUX) is used to supply the isolators, a +12V to +24V supply can be used for sinking drivers, or a 0V supply can be used for sourcing drivers.

11. The Mini-PMAC has an interlock circuit that drops out the +/-15V supplies to the analog outputs through a fail-safe relay if any supply on PMAC is lost.

12. If Option 15 is purchased, the Mini-PMAC has the capability for 2 on-board voltage-to-frequency (V/F) converters. These may be used for 2 “Wiper” analog inputs, or to convert the 2 analog outputs to pulse trains for stepper-type drives. The V/F converters can each take an input of 0-10V referenced to AGND. The pulse trains can be tied into encoder channels 3 or 4 for counting. (It is also possible, but more expensive, to use the first two channels of the off-board ACC-8D Option 2 board.)

Features: