Specifications
IP 240 Counting
8.4 Example for Counting: Fast Filling with Loose Material
The throughput in filling with loose material is measured using a pulse encoder. This encoder
drives the counter on the IP 240 directly.
When the specified setpoint is reached, the valve is closed by the IP 240 hardware.
• Digital output 1 of the first channel on the IP 240 closes an auxiliary relay.
• The auxiliary relay's NC contact is connected in series to a normal CPU digital output (Q4.0).
Starting with the valve closed, the procedure is as follows:
1. The user enters the required amount of loose material in DW 34/35 (initial count value) of the
DB 14.
2. When the pushbutton ”START FILL” (I 5.3) is pressed, the proportioning procedure is activa-
ted, shown by the ”FILLING” indicator (Q4.1).
3. When 0 is reached, the IP 240 closes on the auxiliary relay, thus opening the output ”OPEN
VALVE” (Q.4.0). The valve can close.
4. The state of the counter is only read after a delay (5 s) so that the valve has time to close
properly before the final count is read by the IP. The value is then kept in DD 30 or DD 32 of
DB 14 until a new proportioning procedure is activated.
5. When the ”FILLING” indicator goes out, filling can be reactivated by pressing ”START FILL”.
A proportioning procedure can only be interrupted by pressing ”EMERG STOP”. If filling is to be
resumed where it was interrupted, the actual value in DB 14 must be entered in DD 34 as the
initial count value and ”START FILL” pressed. Otherwise filling would start from the beginning
when ”START FILL” is pressed. As long
as ”EMERG STOP” is pressed, the ”FILLING” indicator flashes
slowly.
If ”FILLING” flashes fast, this indicates a parameter assignment error in the STEP 5 program. The
system can only be restarted after a PLC cold restart or by resetting the ”GROUPPAFE” flag (F 11.0)
reset.
Fig. 8-3. Diagrammatic Representation of the Example ”Fast Filling with Loose Material”
Valve
Pulse encoder
Is controlled over the IP 240
Is connected to the counting input (CLK)
of the IP 240.
Auxiliary relay
IP
240
CPU DAPS
EWA 4NEB 811 6120-02a
8-17