Technical information

562600-000, Issue1.0, March 2014
36 of 57
8.2.4 Machine Envelope Controller (MEC) - Virtual Wall PMERail Ultra
8.2.4.1 PMERail Ultra Virtual Wall Limitation Control
PMERail Ultra complies with NR MDL/004 ISSUE 2. slew limits requirements. Therefore
with a virtual wall slew limit active, as in addition to standard slew limit function (see sec-
tion 8.2.4.2) the system will:
Care should be taken to test that the limit is set correctly. Observe the operational limita-
tions given in section 4.
Once slew limits are set, the internal alarm will sound and the RED
LED will light if the equipment exceeds the either limit. Always
check that the slew limit activates at the set point. The limits cannot be de-
activated if in the alarm state. Observe the operational limitations given in
section 4. Do not travel once a slew limit has been set.
 Activate an amber lamp to show a slew limit is active
 The slewing speed of the machine will be reduced to one of three possible states:
 Linear speed at the tool point will be no greater than 2 m/s when MORE than 2m
(default) away from the set limit.
 Linear speed at the tool point will be no greater than 1 m/s when LESS than 2m
(default) away from the set limit.
 Linear speed at the tool point will be CONTROLLED by PMERail when LESS than
1m (default) away from the set limit. If the tool point reaches 1m (default) away
from the limit, PMERail will:
 Motion cut slew at 1m (default) from the limit to allow PMERail to take over
slew control in the direction of slew travel only.
 To move closer to the slew limit, the
slew joystick must be returned to the
neutral position then back towards
the limit. The warning message show
here will be displayed, linear speed at
the tool point will be no greater than 1
m/s in this state.
 At the limit, motion will be stopped.
 It will be possible to move away from a limit at anytime, the linear speed at the tool
point speed will be increased back up to no greater than 2 m/s.
 The counterweight will not induce the 1m/s state even if it comes within 2m of the
limit.