March 2018
rapidCAST User’s Guide
Page
40
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Defining Positions
The following positions are dependent on vessel speed and environmental conditions. If either of these
conditions changes significantly, re-evaluate the positions.
Setting the Home Position
The Home position is the absolute topmost position, where the probe can’t go up any further. This is the
position at which the encoder value is set to zero.
To set the Home position:
1. Turn power on to the system and start the rapidCAST Interface software.
2. On the Control Module, set the Control Switch to the Local Control position (joystick control)
or PC Control position (use the In, Out, Stop and Speed buttons on the Jog and Teach tab).
3. Move the probe to the topmost position next to the swivel block at the end of the davit.
4. Click the Jog and Teach tab on the rapidCAST Interface software.
5. Click the Define Home button. On the Define Home dialog, click OK.
This step must be done each time the rapidCAST system is powered up.
The winch uses incremental encoders to track the spool position. Unfortunately, incremental
encoders lose their value when power is lost (winch is turned off). When power is regained
(winch is turned on) they always initialize at zero. So, if the winch is currently at the
Launch
position, which originally had an encoder value of 12345 and then somehow power is lost at
this position and subsequently regained, the encoders will now think that they are at value 0
(which is not the case). To recover from this, the probe needs to be manually moved to the
home position and then the
Home
position is set once more.
