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Controls Tech March 7th, 2018 07:54 PM

845P encoder to ML1500 HSC card
Hello everyone, I have finally got some spare time to start back messing around with my test bench and I thought I would add an encoder to my ML 1500. I have wired the encoder up to a 1769 HSC located in slot 1.

Red to A0+
Violet to A0-

Green to B0+
Blue to B0-

Yellow to Z0+
Orange to Z0-

Power is supplied by 3 AA batteries, that read 4.8v(could`t find a power supply).
I have the lights flickering on the A/B of card, haven`t seen anything on Z.

My question is in the Adv.Config for the HSC, counters tab, what would be the operational mode for the 845p encoder? Tried encoder X1 and Pulse internal dir. Downloaded each to processor and did not see any of the values change in the HSC.

Ih8Siemens March 7th, 2018 10:40 PM

See if that guys post helps you out at all.

Controls Tech March 7th, 2018 10:48 PM

Got my inputs working, they only go up to 3 and then reset, not sure whats going on there, gotta play with it a bit more.

Here are my settings.

Counters Tab
Operational Mode= Pulse internal dir.
Max Count= 1000
Min Count= 0
Preset= 1
Update time= 1 ms
Hysteresis= 0
RPM scale factor= 1

Range Tab (tab is in two sections labeled #0 and #1all settings are the same except for the output mask.
Counter Used= Counter #0
High Limit= 1000
Low Limit= 0
Range Active= Within Limits
Output Mask(Hex)=0001 for #0 section #1 section=0002

Ih8Siemens March 7th, 2018 10:56 PM

Check pg65 of this manual. also check out these other pages that might pertain to your situation.
pg 19, pg22, pg24, pg27, pg 35


Controls Tech March 7th, 2018 11:29 PM

I have been scanning thru that manual for several hours, thank you for pointing out those pages, Allen-Bradley puts out great manuals but I often find myself lost in the abundance of information.

Ih8Siemens March 8th, 2018 12:39 AM


Originally Posted by Controls Tech (Post 771172)
I have been scanning thru that manual for several hours, thank you for pointing out those pages, Allen-Bradley puts out great manuals but I often find myself lost in the abundance of information.

No problem, yeah they take actual reading which, when panicking to get something fixed, is hard to do haha. Did you end up figuring it out?

Controls Tech March 8th, 2018 01:37 PM

I have it counting up to 3 but cannot get it to continue counting linear, which makes sense given that a truth table should be
(could put some counters in program and count the pulses add the pulses to get a value) *edit* scratch that I would like for it to count backwards when rotation is reversed, but not sure if this would be the technically correct way, I will mess with it some more when I am off for the weekend. Gotta love night shift!

bernie_carlton March 8th, 2018 02:04 PM

This is a quadrature incremental encoder. Choose X1, X2 or X4 as the mode. If you end up counting backwards swap the 'A' and 'B' connections.

Controls Tech March 8th, 2018 02:49 PM

Hello Bernie, The issue is how to get it to keep counting instead of restarting at zero, when I turn encoder it is tough to tell which way it is counting with it only counting to 3 and then going to 0. Not sure if this is a module set up or something I need to setup in logix 500. Current count Array in the data table is not counting also.

bernie_carlton March 8th, 2018 03:24 PM

I know you posted that you tried it but one of the quadrature modes is what is needed. You may have to restart the program. Then worry about the other stuff. You say that you see the lights. Are they in quadrature - like the PDF for the encoder shows? The 'Z' should only show up as a short pulse once per revolution. Maybe you missed it. Check your configuration or program for a possible reset signal. Sorry I cant check your program.

Possibly capture and post pictures of the configuration pages. Possibly post the configuration table itself.

Controls Tech July 1st, 2018 04:54 AM

Hello Everyone,sorry for the late reply, been extremely busy with school and work, got back around messing with the test bench and encoder and got it working, the entire thing I was missing was I needed to write a 1 to O:1/80 which is the enable bit for the modules counter zero. Thanks for all your help.

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