User`s manual

Installing and Configuring PMAC
Page - 21
3.4 - Connections
Typically, the user connections are actually made to a terminal block that is attached to the JMACH connector by a flat
cable (Accessory 8D or 8P). The pinout numbers on the terminal block are the same as those on the JMACH connector for
PMAC-PC. While the numbering scheme for the pins on machine connectors on PMAC-VME is different from that for
PMAC-PC, the physical arrangement is the same, and PMAC-VME users can use the same terminal numbers on the
terminal block board in following the instructions given below.
Make sure PMAC is unpowered while the connections are being made. Leave any loads disconnected from the
motor at this point.
3.5 - Power Supplies
3.5.1 - Digital Power Supply
1.5A @ +5V (+/-5%) (7.5W)
(Eight-channel configuration, with a typical load of encoders)
- The host computer provides the 5 Volts power supply in the case PMAC is installed in its internal bus.
With the board plugged into the bus, it will automatically pull +5V power from the bus and it cannot be disconnected.
In this case, there must be no external +5V supply, or the two supplies will "fight" each other, possibly causing
damage. This voltage could be measured between pins 1 and 3 of the terminal block.
- In a stand-alone configuration, when PMAC is not plugged in a computer bus, it will need an external five-volt supply
to power its digital circuits. The +5V line from the supply should be connected to pin 1 or 2 of the JMACH connector
(usually through the terminal block), and the digital ground to pin 3 or 4.
3.5.2 - Analog Power Supply
0.3A @ +12 to +15V (4.5W)
0.25A @ -12 to -15V (3.8W)
(Eight-channel configuration)
The analog output circuitry on PMAC is optically isolated from the digital computation circuitry, and so requires a separate
power supply. This is brought in on the JMACH connector. The positive supply -- +12 to +15 volts -- should be brought in
on the A+15V line on pin 59. The negative supply -- -12 to -15V -- should be brought in on the A-15V line on pin 60. The
analog common (important!
) should be brought in on the AGND line on pin 58.
Typically this supply can come from the servo amplifier; many commercial amplifiers provide such a supply. If this is not
the case, an external supply may be used. Even with an external supply, the AGND line should be tied to the amplifier
common. It is possible to get the power for the analog circuits from the bus, but doing so defeats optical isolation. In this
case, no new connections need to be made. However, you should be sure jumpers E85, E87, E88, E89, and E90 are set up
for this circumstance. (The card is not shipped from the factory in this configuration.)
3.5.3 - Flags Power Supply (optional)
Each channel of PMAC has four dedicated digital inputs on the machine connector: +LIMn, -LIMn (overtravel limits),
HMFLn (home flag), and FAULTn (amplifier fault). In most PMACs these inputs can be kept isolated from other circuits.
A power supply from 12 to 24 Volts could be used to power the corresponding opto-isolators related to these inputs. This
feature is not available in the PMAC-PC without Option 1, PMAC-VME or the PMAC-STD board.
3.6 - Overtravel limits and Home switches
When assigned for the dedicated uses, these signals provide important safety and accuracy functions. +LIMn and -LIMn
are direction-sensitive overtravel limits, that must be actively held low (sourcing current from the pins to ground) to permit
motion in their direction. The direction sense of +LIMn and -LIMn is as follows: +LIMn should be placed at the
negative end of travel, and -LIMn should be placed at the positive end of travel.