ACII serial connector wiring confusion

[tleip]

I'm attempting to build my own cable from my ACII to my PC, and also I want to add a pair of leads off of the mini-DIN 8 from the external switch pins on the ACII, so I can hook it to a float switch to alarm on a low water condition.

Neptune has the diagram here:

http://www.neptunesys.com/hardwareFAQ.htm#CABLE

Looking at that, I'm confused, they have pin 1 of the ACII (External Switch Output) hooked to pin 8 of the DB9 connector, which is Clear To Send on the PC side.

Why would they do that? If the port is supposed to be setup with no flow control, what is the point of holding it high by hooking it to the Switch output? And, don't I need it to connect to the float switch?

Can someone clear this up for me??

Thanks,

Terry

 

[mhurley]

Don't be concerned about what the PC definitions of the DB9 are....Neptune uses a completetly custom interface of the Serial connection. Remember, the ACII isn't a PC, so it doesn't need to conform to PC communication standards, so they can use whatever wires they want to communicate however they want.
Shoot them an email, Curt will help you. He did for me....Then I broke my homemade switch and didn't feel like trying to wire one again, so Curt sold me a nice pre-made one.

Mike

 

[tleip]

I'll drop them a line, thanks!

My big confusion is really around them using the external switch pin, which I thought was supposed to be available for me to use - I'll see what they say.

Terry

 

[djfrankie]

Terry let me know what info you obtain on this.

I also did the wiring for the ACII to the PC. I have not tried external switch input on this cable. However, I will be hooking up the ACII directly to a modem and have just ordered the 8-pin din to DB25 modem cable for the modem I will directly connect to the AQII. I found it for $1.00 online (plus $4.95 shipping) and would like to hook it up to a float switch or a water sensor as well.

By the way ...the cable that works for the PC would not work for the modem. Different connections all together.

djfrankie

 

[tleip]

Even though it won't fit, just curious, where did you find the modem cable for $1.00?

T

 

[tleip]

djfrankie, here is their response:

"The external switch output does double duty; it must be connected to pin 8 of the DB9 connector if you have an isolator installed (SERIPC9), and you can also use have it connected to the external switch."

 

[bbragg]

I cracked the connector open on my cable and found only the one pin connected. I left it as is. I opened my controller and then just soldered a single pair insulated cable about 6" long to pins one and two. Then I used a dremel to make a notch in one half of the case shell so that the small cable could drop through just behind their DIN connector. The notch was left small and tight to give mechanical support to the cable from the gripping pressure of the clamshell case. It was tough to solder as the pins are very close on the printed circuit board but I used a very precise Metcal iron for work on SMT circuits. I then just put a simple Molex connector on the other end and I put the mating connector on the wire pair from my float switch. It just snaps in and signals the Neptune when the water in the sump drops. I used a simple sprinkler diaphram valve on the water supply to my RO/DI to control the filling. I had to replace the 24 volt solenoid on the valve with a 120 volt version but they had these handy at Lowes. They also had the fittings I needed to go from my hose bib to 3/4 pipe for the valve and then over to 1/4" water line for the RO/DI ... a miracle.

If you buy the cable from Neptune, the wires in there are line 30 gauge and won't mechanically support much of a connector.

Getting the DIN connector yourself and making your own cable is clearly the best way to go since you won't have to notch the case but I already had the cable handy so what the hell you know.

I love the Neptune unit for this reason. With this final mod, my tank is now fully automated ... pumps, UV, lights, chiller, calc reactor, makeup water, iron and iodine dosing. I just have to feed and clean occassionally. Next to the GEO calcium reactor, I'd say this is my best tank purchase ever.

 

[tleip]

bbrag -- I totally agree, this is such a slick device I don't know how I got by without it!

Once everything is connected, I'll be able to use the remote access to check on things; this is gonna be great for going on vacation!

T

 

[djfrankie]

Even though it won't fit, just curious, where did you find the modem cable for $1.00?

T

I don't really understand when you say it won't fit. It won't fit what?
Your application?

Here's the link as requested

www.provantage.com

HTH,
djfrankie

 

[djfrankie]

I cracked the connector open on my cable and found only the one pin connected. I left it as is. I opened my controller and then just soldered a single pair insulated cable about 6" long to pins one and two. Then I used a dremel to make a notch in one half of the case shell so that the small cable could drop through just behind their DIN connector. The notch was left small and tight to give mechanical support to the cable from the gripping pressure of the clamshell case. It was tough to solder as the pins are very close on the printed circuit board but I used a very precise Metcal iron for work on SMT circuits. I then just put a simple Molex connector on the other end and I put the mating connector on the wire pair from my float switch. It just snaps in and signals the Neptune when the water in the sump drops. I used a simple sprinkler diaphram valve on the water supply to my RO/DI to control the filling. I had to replace the 24 volt solenoid on the valve with a 120 volt version but they had these handy at Lowes. They also had the fittings I needed to go from my hose bib to 3/4 pipe for the valve and then over to 1/4" water line for the RO/DI ... a miracle.

I like what you did here...Thanks for posting.

djfrankie

 

[djfrankie]

djfrankie, here is their response:

"The external switch output does double duty; it must be connected to pin 8 of the DB9 connector if you have an isolator installed (SERIPC9), and you can also use have it connected to the external switch."

So from pin 1 > 2 ?

thanks,
djfrankie

 

[tleip]

Pin one needs to be connected both to pin 8 of the DB9 connector, and to the external switch.

T

 

[djfrankie]

Pin one needs to be connected both to pin 8 of the DB9 connector, and to the external switch.

T

My bad you're right.

Now, if going from AQII to Modem it would be from PIN 1 > PIN 2 on the AQII to activate the external switch.

 

[vanburen]

Great thread!

So if all I want to do is rig up a mechanical switch, I could use the $1 modem cable and chop off the non-minidin end? Then just use the wires from pins 1 and 2? Thanks!

 

[tleip]

Sounds like it should work

If Switch1 CLOSED Then ALM ON

This way I can get alarmed for low water. I bought one of those $5 float switches from ebay and hooked it to the switch. It works great on my workbench, now to move the whole thing to the sump!

MY Question: If I'm not using the ORP prob, can I use this as a second external switch (i.e. if I hook up a BNC connector to the ORP jack and if the connection is completely open or closed, could I get a consistent value I could use?

Terry

 

[mhurley]

I doubt it.....My guess is that the BNC channel is used to receiving data values like 300 or 400. The external switch is a simple binary yes/no.

 

[tleip]

I'll pick up a BNC and try it, I was thinking something like

If ORP = 0 Then XXX ON (connection closed)
If ORP > 0 Then XXX OFF (conenction open)

 

[vanburen]

What does the ORP read with it on but the probe disconnected? Wouldn't that give you an idea without having to get a BNC? You could short the terminals to see what the other response is.

 

[tleip]

Shorted it seems to read zero, and open it reads > 0, but not very consistently. The wire I used isn't a good connection on the tiny female part of the jack, so I was hoping that a better connection might yield more consistent results. What I really need is a EE-type to explain how it works...

T

 

[bbragg]

The ORP input likely is hooked to an OP AMP setup to provide for a specific probe impedance. There's probably going to be a little error or offset issue between the OP AMP and the ADC of the controller (Analog to Digital Converter) so you might want to select a value other than simple zero to account for the error. For example, 5. Just a guess though. Better to experiment.