42/52 Commissioning
Bosch Rexroth AG
, VT-MRMA1-1, RE 30214-B/03.2019
– When a voltage greater than +8.5 V is applied, positioning control and the output
stage are activated.
– Blocking of positioning control and the output stage when a voltage of less than
+6 V is applied.
The valve remains in the self-locked position.
Make sure that the enable signal is only given when a new actuating process of
the valve is going to take place. When the new working pressure has been
reached, the enable has to be reset again!
• “Ready” signal (24 V output):
The “ready” output is connected against the 24 V operating voltage, when the fault
detector has not established a fault (see “Fault detection (8)“ on page 20).
• “Position command value reached” signal (24 V output):
This signal is used for monitoring the valve position controller. The output is
connected against the 24 V operating voltage when the actual valve position value
corresponds to the valve position command value resulting from the pressure
command value.
When the ramp is active, the signal for ”position command value reached” is
connected to 0 V for the duration of the ramp.
• Pressure switch signals A and B:
Pressure switch signals A and B monitors the actual pressure value for being within
the selected limits.
For the system, this results in the following signal and adjustment sequence:
Table 35: Signal and adjustment sequence
Measure
Signal and adjustment sequence
Terminal
Status
Query of state signals
Output “ready for operation”
10
High *
Output “position command value reached”
9
High
Outputs of pressure switch signals A and B
13, 14
High
Functional test of pressure
switch signals (increased
safety)
Apply new pressure command value for checking purposes (it should be
significantly greater (smaller) than the current pressure command value)
6
“Position command value reached” becomes inactive
9
Low *
One of the two pressure switch signals A or B becomes inactive (delay
depends on set ramp time)
13, 14
Low
Provide desired pressure
command value from the
control
Apply new pressure command value
6
Enable internal controller and
output stage
Set enable
7
High
Actuating process on the valve starts:
The position adjustment signal “position command value reached” becomes
inactive for the duration of the actuating process
9
Low
Actuating process completed:
Positioning signal ”position command value reached” is re-activated
9
High
Pressure switch signal A (pressure is present within the agreed tolerance
range)
13
High
Pressure switch signal B (pressure is present within the agreed tolerance
range)
14
High
Permanently active
monitoring functions
