?> Sinamics V20 get permition to run from Modbus & x1 digital signal

Several ways come to mind.

1. Easy.  Do all the logic in PLC.  No extra wires.

2. Medium.  Use your lockout to switch command data sets.  Locked out, CDS1, means control by terminals.  Since there will me no On command, it won't run.  Normal would CDS2, control by MODBUS.  Need to add wiring.

3. Safest.  Normal powers a contactor that turns on the common power to all the drives. Lockout is no power.

Jeff Casagrande

Several ways come to mind.

1. Easy.  Do all the logic in PLC.  No extra wires.

2. Medium.  Use your lockout to switch command data sets.  Locked out, CDS1, means control by terminals.  Since there will me no On command, it won't run.  Normal would CDS2, control by MODBUS.  Need to add wiring.

3. Safest.  Normal powers a contactor that turns on the common power to all the drives. Lockout is no power.

Thanks Jeff for answering.. much appreciated.

(3) is not an option for me - it gives an uncontrolled stopping.
The conveyor should use a deceleration at all times.
..and not to worry it is not intended as a safety circuit.

(1) is in place for plan B.
The client however wants to "see" the connection.

Wiring (2) is not an issue and this would be plan A.
But I have just no idea what you mean by "CDS"...
I will go look it up and see what you are hinting at.

Cheers.
w

okay...

According to the manual, the switching of
command data sets (CDS) can be done via P810 and P811.

So if I want to to use DI1 to switch between
CDS0 and CDS1 (guess)

P0701[0] = 99    ;BICO function for CDS0 on DI1
P0701[1] = 99    ;BICO function for CDS1 on DI1

P0810    = 722.0 ;linking to DI1 via r0722.0

..would that be right?

I was really expecting a type of [&] action on the ON/OFF
action that combines Modbus and DI1.
Is there not a way to program DI1 per BICO to be an enable (like on servos)?

w

Now a different idea.
Attached is an extract of the manual.

I would be most thankful if someone could confirm my idea.

P0701[0] = 99    ;BICO function on DI1
P0849[0] = 722.0 ;secondary OFF3 linked to DI1 = OFF

From the text it seems that P849 will do its job regardless is the main commands come from Modbus. The quick stop ramp settings (P2167 & P2168) applies.

Any suggestions?
w

William_B

I was really expecting a type of [&] action on the ON/OFF
action that combines Modbus and DI1.
Is there not a way to program DI1 per BICO to be an enable (like on servos)?

w

 I believe there are some Free Function blocks you can play with.  You could AND your MODBUS ON with a DI for the ON command.

Jeff Casagrande

 I believe there are some Free Function blocks you can play with.  You could AND your MODBUS ON with a DI for the ON command.

That was my first instinct.
I have rejected the idea though.

My opinion follows.. which may be flawed..
It seems that the Modbus links directly to the control registers.
There is no "in-between" bit to have Modbus write to
so that it can be combined with physical inputs.

I would be most happy if I am wrong and can find a way to use FFBs.

Jeff - thank you very much for your interest in my problem.
w

New idea.

How about having the drive
be controlled by the terminals (P700 = 2)
but get the frequency setpoint from Modbus (P1000 = 5).

OPTION 1

If it is possible to have Modbus still R/W control digital output 2 via Modbus address 40015 then the Modbus can switch an input via the output.

The main switch is wired through DO2 on the normally open of the relay to DI1. DI1 is configured to run the drive. So both should be in ON before the drive runs.

OPTION 2

Have an FFB combine DI1 and the frequency setpoint to give permission to the drive to run.

UPDATE:
Control via communication and digital inputs was not successful.