Philips CARDIOMD, Service Manual

Page: 39 / 466

Detailed Description
1MAN0158-H11 04-2005 CSIP Level 1
CardioMD Service Manual
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3-15
•
12 digital outputs – for various purposes, including table movements
•
One clock output to be used for reading of the absolute position encoders
•
Motor control output ports including:
-
Amplifier enable
- +/– 10 V motor voltage.
Furthermore, for debug and diagnostics, 5
×
10 yellow LED’s are placed on the motion controller
front. These LED’s are further described in Chapter 5 Diagnostics .
3.2.3.5 Mutual Motion Controller Monitoring
The two motion controllers communicate via a dedicated high-speed synchronous serial interface.
This interface is also used for mutual supervision of the proper functioning of the two motion
controllers.
The Linear controller transmits the X and Y incremental encoder positions to the Rotate controller
which in turn compares these to the absolute encoder positions. This ensures that the encoders are
connected correctly and working properly. In this way the Rotate controller also supervises the
proper functioning of the Linear controller.
The Linear controller receives regular sync messages from the Rotate controller. A watch-dog
function in the Linear controller assures that these messages arrive within a certain time frame.
If either of the units detects that the other is not running properly (runaway condition), the signal
OUT00 is de-activated (set HIGH). This removes all power from the motors.
However, it is possible to override this assertion (e.g. during service) by means of DIP switch
SW8 (the same switch is used for overriding calibration status). There is no reset possibility, i.e. if
one controller has activated the runaway signal, both controllers must be reset before normal
operation can be resumed.
3.2.3.6 Motion Limits
Each detector motion axis is equipped with software limits, ultimate stop limit switches and
mechanical end stops.
When the motions are correctly calibrated, the software limits are at the following positions:
Motion Axis Low End Stop High End Stop
Detector rotate – 90° + 180°
Detector vertical 231 mm 1193 mm
Detector horizontal 0 mm 495 mm
Table 3.6 Software limits for system motions
If the detector is positioned beyond the software limits, the hardware ultimate stops will be
triggered. When one ultimate limit switch is triggered, power to all motors is removed.