Gonna use the tile board for my test box

[zxninja]

Hey there, I am going to build a test box and am worried about the difficulty in wiring my thumbwheels and LED display to the I/O cards. I have no experiance in wiring these types of I/Os up...any help would be great!! will be using A.B. plc 5 family.

Thanx
JEFF

 

[Danocane]

PLC5/15 Simulator Board

Here is a link to another thread I posted some time back with an image of the PLC simulator I built.....

PLC5 Simulator

There are terminal strips right below the PLC Chasis. I connect cables to these terminals to the devices I want to control. I had originially built this unit to remotely ignite a fireworks display. Since then we have used this system to connect many other electrical and mechanical devices to test programming controls on. I am in the process of installing molex block connectors to speed up the wiring process when relocating and reassembling to equipment.

BTW this years fireworks display is going to be mounted on a pontoon boat and floated onto the middle of a 9 acre pond. Should be interesting to say the least.

 

[zxninja]

Wow!!! a little over my head there, but it looks like a fun poject you put together. I just need some help with the wiring of a thumbwheel and LED display. They will be used to input, and show, output value for various projects. Thanks for the lesson in fireworks though!!!!

 

[Ron Beaufort]

thumbwheel crash course -

Jeff,

I’m short on time but here is a crash course in how MANY (but not all) thumbwheel switches work -

[attachment]

Notice that each thumbwheel digit requires four wires - and so four digits works out to sixteen wires - which corresponds perfectly with the number of inputs available on a 16-bit input module. You don’t have to wait until you actually wire up your thumbwheels to play around with these ideas. Just force the bits on one of your input modules into various valid BCD (Binary Coded Decimal) patterns to simulate inputs from the thumbwheels. Remember: Valid BCD patterns represent the decimal digits zero through nine - the same system used by most thumbwheel switches.

Referencing the example above, the question remains: “What the heck am I going to do with the decimal value 4660?” The quick answer is: “Nothing.” Now add a rung using an FRD (From BCD) instruction to take the value from your input word (example: I:001) and put it into a suitable destination (example: N7:0). Again using the example above - the value should now be 1234 - ready to use for a PID setpoint - or a timer preset - or a counter preset - or for any other type of input which comes from the equipment operator.

In practice, we normally use a pushbutton (often it’s labeled “Enter”) and an ONS (One Shot) to condition the FRD rung. That way the operator can fiddle around with the thumbwheels until he finally gets the correct value dialed in - and then he presses the Enter button to actually “send” his setting over to the machine.

 

[zxninja]

Perfect Ron, thanks...that is just what I was looking for!!! And to hook up a diplay to show these values??

Regards
JEFF ALFORD

 

[Ron Beaufort]

there are exceptions to every rule - but ...

assuming that you're using 7-segment displays (very common) then hook up four wires from a suitable output module to each digit that you want to display - then program a rung with a TOD (To BCD) instruction to take your "I want to display this decimal number" location (example: N7:1 = 1234) and convert it to the proper BCD (format ready for display) at your output module's address (example: O:002) -

and suppose that you only want to drive two digits of a display - question: Is there any way to "reserve" the eight extra bits (on a 16-bit output module) and use them for "normal" (controlled by regular-old ladder logic) outputs? - answer: yes - research and experiment with MVM (Masked Move), etc.

PS - want to play "hard ball"? - if your display is a four digit display and will accept "strobing" inputs (most are and will), then experiment and come up with a way to use just eight wires (four for the digit value and four for the strobe lines) to drive all four digits on the display - basic idea: move the one's digit value onto the digit value wires - then pulse the "ok-one's-digit-this-is-for-you" strobe line - next move the ten's digit value onto the digit value wires - then pulse the "ok-ten's-digit-this-is-for-you" strobe line - next ... (well, you should have the idea by now) - done correctly this gets 16 bits worth of "display power" using just 8 bits of the output module - but it DOES take some "beyond beginner" programming to get it done right - ("right" in this sense means "no annoying amount of flicker as the display changes value)

 

[Guest]

Thumbwheel Switches

zxninja,

Sorry I didn't get back to you about your other questions. I've been out in the country mowing, trimming and building display racks. I only have phone modem internet connection out here. Much slower than the broadband connections I use in town, so don't get online much.

Ron answered your thumbwheel question much better than I could have....Thanx Ron.

I had a project several years ago in which I had to inform the shipping office clerk which one of 24 shipping lanes was blocked or jammed. This had to be done on a shoestring budget so I could not purchase something like a HMI. All I had was a 1771 12 to 120 VAC output card (would have been simpler with a TTL output card). I powered the outputs with a 12 vac transformer and then built a perfboard circuit to convert each of the 12 vac output lines to 5 vdc signals (tiny bridge rectifiers and 5 volt zener diode for each output line). These signals were connected to IC's (BCD to 7-segment divers) This only used 2 7-segment displays and the PLC program would detect the jammed lane then flash the appropriate digets to inform the shipping office clerk. The clerk could then page the shipping lead to clear the jam. This sytems worked very well for several years, until we built a new shipping building with sixty-six shipping lanes and dock doors. this project of course had a big budget and I got to set up some Panelview systems to track jams, fulls and product flow conditions.

Ron's information on the LED Displays is right on also.

Thanx Dan

 

[Danocane]

Country Phone Lines

My system logged me off while I was typing the above post....so it was sent as Guest. Sorry about that.

Thanx Dan

 

[Sherlock4me]

Yeh Ron, You have a gift at teaching. Thanks for the youtube videos and everything here. Hope to see you in the bootcamp soon. Thanks to everyone here. Helping us all you are.

Jeff