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Old November 11th, 2011, 12:21 PM   #1
juanmdx
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Absolute Encoder and Fast Input Card

Hello,

I'm currently working on a 1769-L32E CPU (compaq logix) with a 1769-IQ16F (fast input card) and a 845D Absolute Encoder (natural binary code), it's my first time using absolute encoders and I'm not shure how should I do it.

I connected the first ten inputs of the card to the encoder's cables (according to the manual) and then power to the encoder (according to manual), but nothing, I can't read anything, I just get 1's (except for the input 0, it remains 0), I have turned the encoder slow and fast and inputs doesn't change...

Can anyone tell me what I'm doing wrong please...



Thanks and best regards

Juan
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Old November 11th, 2011, 01:16 PM   #2
kamenges
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It sounds to me like a voltage reference issue. The signal coming from the encoder is not what the input module is looking for. What is the full part number of the encoder you are using and exactly how is it wired, including power source and common.

Keith
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Old November 11th, 2011, 01:24 PM   #3
juanmdx
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845D-SJDZ25ANDW4

It is wired like this:
A - Input 0 on the 1769-IQ16F
B - Input 1 on the 1769-IQ16F
C - Input 2 on the 1769-IQ16F
D - Input 3 on the 1769-IQ16F
E - Input 4 on the 1769-IQ16F
F - Input 5 on the 1769-IQ16F
G - Input 6 on the 1769-IQ16F
H - Input 7 on the 1769-IQ16F
J - Input 8 on the 1769-IQ16F
K - Input 9 on the 1769-IQ16F
L - No use
M - No use
N - No use
P - No use
R - To change direction, not always on use
S - Only 24VDC when I want to reset it
T - 0VDC (well I put the 0VDC reference here the LEDs on the card didn't showed up, when I disconnected the LEDS came up, so I'm not shure it needs it)
U - This is the latch control, not shure how to use it..
V - 24VDC



Thanks
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Old November 11th, 2011, 03:11 PM   #4
Mickey
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As I read it the 24VDC power supplies common needs to be connected to pin T. Also that same common needs to be connected to the input card's common.
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Old November 11th, 2011, 04:06 PM   #5
juanmdx
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That's right, pin T is to the common of the 24VDC powersupply, and that same common is connected to the cards common, but nothing, I don't get anything on the card's inputs..., but if I unplug the encoders common (pin T to noting), I get some inputs, but they don't change...

Whan can be wrong?
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Old November 11th, 2011, 04:15 PM   #6
kamenges
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You have the non-latching version of the encoder so you don't need to worry about the latch line.

However, the encoder is designed with NPN outputs. They pull the encoder line to ground when it is active. So you need to wire up the input card to work wit hsinking inputs. This means connecting 24VDC to the DC COM 1 and DC COM 2 terminals on the input card.

Keith
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Old November 11th, 2011, 05:11 PM   #7
juanmdx
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Thanks for the NPN tip (well, if I'd read all the datasheet I would've noticed that..., sorry), so I connected 24VDC to the COM's, but still not getting any input..., anymore ideas?
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Old November 11th, 2011, 05:22 PM   #8
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Sorry, another misscommection, it's working already, it waas the NPN thing
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