MID-7654/7652Servo Power Motor Drive User Guide 6 ni.com
The ENABLEswitch enables or inhibi ts the servoamplifiers. If the
ENABLEswitch is in the inhibit position (OFF), the amplifier output stages
are inhibitedand the yellow LEDs for all axes illuminate. See the Front
PanelL EDs section of this guide for more information.
Both the ACPOWER and ENABLE switches can inhibit the servo
amplifiers.However,as long as the ACPOWER switch is on, only the servo
amplifieroutput s tages are disabled. The remaining circuitry remains
active,including the quadrature encoder circuit.
Warning You must change the MID-7654/7652 main input fuse on the rear panel if you
changethe line voltage from the factory setting. Refer to the Specifications section of this
guide for fuse specifications.Refer to the Modifying the Power Entry Module section for
moreinformationonhandlingthepowerentrymodule.
Host Bus Interlock Circuit
The MID-7654/7652 has a host bus interlock circuit that monitors the
presenceof +5 V from the host computer and disables the MID-7654/7652
when the voltage is not present or falls out of tolerance. This circuit shuts
down the servo amplifiers for all axes by activating the inhibit when the
host computer is disconnected from the MID-7654/7652 or inadvertently
shut down. Activation of the host bus interlock circuitry illuminates the
yellow LEDs (middle row) of the LED status array for all axes. See the
FrontPanelLEDssectionof this guide for more information.
Front Panel LEDs
Thefront panel LEDs consist of a single green LED to indicate if the mai n
5 V power is active. If the DC power supplies are active, the green power
LEDilluminates. If this LED fails to illuminate, check the power cord and
the main input fuse on the front panel.
An LED status array of 3 rowsby 4 columns on the MID-7654 or 3 rows
by2 columns on the M ID-7652 providesa variety of status information .
Referto Figure 1 for the location of the front panel LEDs. The LED status
array isarranged by motor axes. Each of the four columns represents an
axis, and each of the three rowsrepresents a particular status. Table1
summarizesthe axes and statuses to which the different LEDs in the 3 ×4
or 3 ×2 array correspond.