PMAC Product Guide Note: The DAC screen of the EZ-PMAC Setup Software allows outputting a particular voltage to the appropriate DAC output which can then be measured with a voltmeter. Amplifier Enable Signal (AENAx/DIRn) Most amplifiers have an enable/disable input that permits complete shutdown of the amplifier regardless of the voltage of the command signal. PMAC’s AENA line is meant for this purpose. If not using a direction and magnitude amplifier or voltage-to-frequency converter, use this pin to enable and disable the amplifier (wired to the enable line). AENA1/DIR1 is pin 47. Jumpers E17A through E17D control the polarity of this signal and the default is conducting enable.
The amplifier enable signals are controlled by chip U54. If jumper E100 connects pins 1 and 2, U54 will be supplied from the analog A+15V supply which can be isolated from the digital circuitry. If E100 connects pins 2 and 3, U54 will be supplied from a separate A+V supply brought in on pin 9 of the J8 JEQU connector. This supply can be in the +12V to +24V range and can be kept isolated from both the digital and analog circuitry. This also allows 24V operation of this signal. By default, the PMAC Lite is provided with a sinking output driver IC (ULN2803A or equivalent) in U54. In this configuration, jumpers E101 and E102 must connect pins 1 and 2 to supply the IC correctly.
If this IC is replaced with a sourcing output driver IC (UDN2981A or equivalent), E101 and E102 must be changed to connect pins 2 and 3 to supply the new IC correctly. Warning: A wrong setting of these jumpers will damage the associated output IC. For any other kind of amplifier enable signal, such as a 5V signal, a dry contact of a relay or a solid-state relay can be used: Machine Connections 31