Host Engineering Forum
General Category => CTRIO and CTRIO2 => Topic started by: scott.lawrence on December 02, 2011, 04:42:44 PM
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I have an application using two H2-CTRIOs to run three stepper drives. Each axis has a 'Home' proximity switch (24VDC sourcing) with signal wired to the respective 'C' terminals & 0VDC wired to the 'M' terminals.
Wanting to add a linear quad encoder, I purchased the CTRIO-TTL Annex card to bring these encoders into the PLC.
Looking at the drawing for the Annex, it shows wiring the 24VDC positive into the 1M/2M terminals of the CTRIO. Since the annex doesn't have an Index terminal, can I still use a home prox with this if I change it to sinking?
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I didn't even know the CTRIO-TTL Annex existed. We, when needed, had been using a buffer (much higher priced by the way) from another company. Since they are sinking circuits then your 'C' signal will have to be changed to sinking also. But it should work well.
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thanks, Bernie... I figured it would work, but just wanted clarification.
hey Host Eng mods, try incorporating index outputs into the next version of the annex, or will the new CTRIO be able to interpret TTL signals?
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The new H2-CTRIO2 has the same HW input configuration and signal levels allowing higher frequencies up to 1MHz. It can also be made available in a TTL input version that includes the annex components. This model will remove the diode bridges that give us the sink/source option.
So for TTL operation, the input "M" terminal will need to be wired to 9-36VDC. A new TTL ground terminal will be required for the 0V connections of both the TTL signals and the 9-36VDC power supply.
If you want to make use of a TTL Home signal on the same CTRIO channel as the encoder you would need to use a sinking circuit style encoder as well.
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thanks Tim for the info
a little filler information...this is actually an optical linear encoder, and since it's a cut-to-length tape, it uses stick-on index markers
since I actually have three annex boards, I believe I could tie the index + to the second A+, and just use one annex per drive. I'll let you guys know how this turns out next week, as I'm installing the encoders this week-end....
***Update***
it worked!! YAY!