How to make a Latch

emotero · Jun 1, 2007

Hi,

I recently purchased the E10-npn PLC and I need to control some hydraulic valves. I basically want to do this:

http://www.plcs.net/chapters/latch14.htm

The only difference is I want to use a Visual Basic program as the 'hand' or on/off switch.

I have never programmed PLCs before and have limited knowledge of micro-controllers.

I need to control 4 hydraulic solenoid valves. Normally, the valves will be 'off' and open, but when the machine is operating, some of the valves will be turned off selectively for periods of 45-60 minutes at a time.

Thanks for your help! I really appreciate it! Hope to learn more about PLCs.

eva

milldrone · Jun 2, 2007

Welcome to the forum,

emotero said:
I recently purchased the E10-npn PLC and I need to control some hydraulic valves. I basically want to do this:

http://www.plcs.net/chapters/latch14.htm

I tried the Trilogy Java demo and I couldn't find the "set" "reset " coil instructions. The example on this site http://www.plcs.net/chapters/level12.htm , will give you simular results

If you have some questions just ask.

emotero said:
The only difference is I want to use a Visual Basic program as the 'hand' or on/off switch.

I'm not a VB guy so I cant help you here.

A word of warning. My guess is the outputs of this plc will not handle a hydraulic solenoid coil by themselves. At the very least they will need some counter emf suppression. Hydraulic solenoid coils are as a group are some of the toughest outputs a plc has to drive. A DO5 hydraulic solenoid valve (very common in my industry) will commonly be 120 volts and approximately 1 amp holding current and 6 amp inrush.

Jason_Adams · Jun 2, 2007

I think you are right about the outputs Milldrone, if the outputs are "npn", which it looks like they are, he will need to sink the output to a relay that has a dc supply attached to the other side of the coil. And of course include a diode accross the coil in parrallel.

According to this he has exactly one amp max current on the outputs before making smoke.

http://www.tri-plc.com/e10intro.htm

khalil · Jun 2, 2007

I dont know if I understand correctly, but if you wanna do a flip flop circuit using Tbasic , or tri-plc they have something called ladder + basic you can write the following in a function and call that function from your ladder editor:

IF DM[1] = 0 THEN
SETBIT OUTPUT[1], 0
DM[1] = DM[1] + 1
ELSE
CLRBIT OUTPUT[1], 0
DM[1] = 0
ENDIF
-------------

I hope this is help..

PeterH_DK · Jun 3, 2007

Tri PLC support

khalil said:
I dont know if I understand correctly, but if you wanna do a flip flop circuit using Tbasic , or tri-plc they have something called ladder + basic you can write the following in a function and call that function from your ladder editor:

IF DM[1] = 0 THEN
SETBIT OUTPUT[1], 0
DM[1] = DM[1] + 1
ELSE
CLRBIT OUTPUT[1], 0
DM[1] = 0
ENDIF
-------------

I hope this is help..

Well Khalil wrote it beautifully in Basic, but you can also do it very simply in Ladder, by inserting at latched output ( choose function -> Latching Relay/Output.
This site is very ressourcefull for all sorts of PLC related problems - but I doubt if anybody else here, except you and my self use Tri-Plc, so if you have some very specific TRI-Plc Questions you may try the Support forum of Tri Plc (http://www.tri-plc.com/yabbse/index.php?board=1)

/Peter

emotero · Jun 3, 2007

Solenoid Isolation Vavles

Thanks so much for all the advice! I'll need to look more in detail at the code and links you provided when I get to work tomorrow morning.

The solenoid vavles I'm planning to use are these - they are called 'isolation valves' on the website

http://www.bio-chemvalve.com/spec.asp?id=5

The spec sheet shows that the model 100T3 uses 0.16 Amp holding current at 24Volts (2nd page). It doesn't say what the rush current is. Maybe six times as much?

http://www.bio-chemvalve.com/Isolation_Valves.pdf

Do you think the E10npn+ will be able to handle four of these solenoids? I believe each output can handle 1 AMP. This is the first time I will work with these valves, so I do not know what to expect.

I also purchased the E10 npn relay, which is supposed to output 2 Amps of current. Perhaps this would be suitable?

Thanks! Appreciate all the feedback!

eva

khalil · Jun 3, 2007

emotero said:
Thanks so much for all the advice! I'll need to look more in detail at the code and links you provided when I get to work tomorrow morning.

The solenoid vavles I'm planning to use are these - they are called 'isolation valves' on the website

http://www.bio-chemvalve.com/spec.asp?id=5

The spec sheet shows that the model 100T3 uses 0.16 Amp holding current at 24Volts (2nd page). It doesn't say what the rush current is. Maybe six times as much?

http://www.bio-chemvalve.com/Isolation_Valves.pdf

Do you think the E10npn+ will be able to handle four of these solenoids? I believe each output can handle 1 AMP. This is the first time I will work with these valves, so I do not know what to expect.

I also purchased the E10 npn relay, which is supposed to output 2 Amps of current. Perhaps this would be suitable?

Thanks! Appreciate all the feedback!

eva

Eva,

you can connect your NPN output (wich is the negative signal, ie, you supply positive to the load and the PLC NPN output will supply the negative signal to the load) to a relay! and then connect your valve to the relay..a relay can carry enough current to activate the valve..

I must say, if high speed operation is requied then instead of Relays..you can use solid state relays...

hope this help. Khalil

How to make a Latch

emotero

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milldrone

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Jason_Adams

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khalil

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PeterH_DK

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emotero

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khalil

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