Operation; Pre-Act Function - Siemens Milltronics BW500 Operating Lnstructions

Operation

Once the BW500 relays are connected to the process logic, and it is programmed, the
BW500 is ready for totalizing the batch and stopping the process when the batch setpoint
is reached. The batch operation: start, pause, resume, and cancel are controlled
externally by the process control (e.g. PLC)
Place the unit in the RUN mode.
Press ALT DISP until the batch screen is displayed.
Rate 0.00 kg/h
Batch 0.00 kg
Start running the batch.
The display will show the rate of material flow and the batch total, as well as the batch
setpoint. If pre-warn is used, relay contact is open.
When the batch total reaches the pre-warn setpoint, if programmed, the alarm event is
removed and the assigned relay contact is closed.
Rate 123.4 kg/h
Batch 17.00 kg
The process continues, and when the batch total reaches the batch setpoint, the alarm
event is displayed and the assigned relay is actuated (contact opened). Typically the relay
contact would be integrated into the batch control logic to end the process.
Rate 123.4 kg/h
Batch 20.00 kg
When the next batch is to be run, pressing
providing a momentary contact closure across an auxiliary input (programmed as batch
reset, P270 = 8), sets the alarm display and resets the batch total to zero, and the relay
contact to its closed state.
Rate 0.00 kg/h
Batch 0.00 kg
Note:
• The batch totalizer can be viewed as a read-only parameter (931-05), using single
Parameter access through any programmed communication port.
• The batch setpoint can be modified in RUN mode using the up/down arrow keys.

Pre-act Function

If repetitive batches are being run, the pre-act function (P568) can be enabled to
automatically trip the setpoint relay before or after the batch setpoint is reached to
assure best batch accuracy.
7ML19985DK05Milltronics BW500 and BW500/L - OPERATING INSTRUCTIONS
e.g relay 1 is programmed for pre-warn,
SP: 20.000
P100-1=7
SP: 20.000
ALM 1
e.g. relay 2 is programmed for batch set-
point, P100-2=8
ALM 12
and then
SP: 20.000
on the local keypad, or
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