Step & Direction outputs for SureServo Amplifiers

[RogerFroud]

It looks like I'm going to need two PCBs to make a neat job of interfacing my Linear Encoders and SureServo AC Servo Amplifiers. Thanks do the help received so far, I've designed the attached boards.

The KANALOG Linear Encoder interface will likely have 90 degree headers that screw directly into the JP1/JP2 terminals. The two pin connector supplies the +5V to the Linear Encoders, and the 9-pin D connectors allow the Linear Encoders to plug straight in.

The KFLOP Step and Direction interface uses JP4 VDD5 & GND to power two Differential Line Driver chips 75ALS174 which have compatible input levels with the 3V3 outputs IO16_3V to IO23_3V terminals. It bolts directly on top of the KFLOP board, with a 16Way ribbon cable.

I would be grateful if someone could cast an eye over the KFLOP JP4 pin allocations I've used for the four Step & Direction channels to confirm that I can use those for X,Y,Z & A Channels that use the KANALOG JP1/JP2 Linear Encoder Feedback inputs. I've just allocated them sequentially. I looked at one of the examples, and that seems to be similar to what was done there.

[TomKerekes]

Hi Roger,

I already explained in your previous Thread Step/Dir signals are not available on those pins.

[RogerFroud]

Ok, my mistake but now I'm very confused. You did contradict yourself at the end of that thread though, which is what I picked up on...

"So to be crystal clear... the Servos are to be driven by Step & Direction pulses from the KFLOP JP4, and the position feedback is to be only from the Linear scales on the KANALOG JP1/2
Is that definitely ok?

yes"

The link you posted takes me to a page which says this...

"However the first 4 Step/Dir outputs can be multiplexed to connectors JP4 and JP6 if desired. This may be required if JP7 is used for some other purpose such as interfacing to the Kanalog I/O Expander." The table clearly shows JP4 with Step & Direction labels against them. It's very confusing.

This circuit example shows KFLOP JP4 and JP5 both being used for Step & Direction outputs while KANALOG also appears in the circuit.
https://www.dynomotion.com/wiki/index.p ... 9-2018.pdf

So, rather than going round in circles, what pins can I use for Step & Direction outputs for the 4 channels? Where do I get to them on the KANALOG board if I can't get to them on the KFLOP board? Maybe this isn't possible with the KANALOG board, and I'll have to make my own interface for the KFLOP directly instead. I do hope not, because that's a lot more work.

This is where a full schematic of the KANALOG interface would be useful, because it would be clear what pins go where.

[TomKerekes]

See here for pins Step/Dir are available.

[RogerFroud]

Ah... finally the penny has dropped. I thought you were saying that you couldn't use JP4 for this.

So, now I see that two channels of Step and Direction outputs can be routed through JP4 and another four on JP6

I've attached a modified schematic of what is hopefully the right configuration.

Thanks for your patience.

[TomKerekes]

That looks correct except missing GND connections.

[RogerFroud]

Thanks for that. I assume you're referring to the IC GND connections? Those are hidden by the CAD package, as are the VCC power connections. They are defined in the symbol so you don't have to wire them all up. The VCC and GND primitives allow other connections to be made to them where required, such as the enable pins on the ICs.

Hopefully I've got the interfaces right now. When the boards arrive, I'll measure the exact positions of the connectors and the pitch of the JP2/JP3 ones that appear to be 0.2" but could be 5mm. You wouldn't happen to know the make and part numbers of those?

[TomKerekes]

The screw terminals are Phoenix Contact 1934926 at 5mm pitch.

[RogerFroud]

That's great, thanks for the information