Sensor & Control Assy Development and Build

[hamishmb]

Ah okay. I've also updated the shebangs for my old tests (sockets class and SSR) to make sure they use Python 3.

[TerryJC]

Herewith please find a couple of annotated photographs of the almost completed interface box, built to house the Lady Hanham SAC.

Penri,

Now I've got the finished box here, I have some questions:

1. I'm assuming that the patch panel is being used to make it easier to make-off the ends of the incoming Cat 5 Ethernet cable, as with the Wendy box. I note in the finished version that the patch panel currently has three cables terminated on it, all coming from the three Ethernet cables which emerge from the cable gland that you labelled 'Ethernet links to Gate Valves'. There is currently no Cat 5 cable from the 'backbone' (of course), but the gland that you labelled 'Ethernet backbone I/O currently carries the big blue 12 V cable that splits into three for the Gate Valves. From this I assume that the incoming Ethernet backbone will now use the vacated '12 V DC Out' gland.
2. The incoming Ethernet backbone will therefore also go to the patch panel, which will then link everything to the Switch. Did you intend that the Lady Hanham SAC Ethernet cable would plug directly into the Switch or go via the patch panel? The former is simpler, but the latter means that everything will be labelled.

Terry, do you think the connectors should be labelled and if so what would you like each called? If labelled I'll add the same information to the cable assemblies connecting the I/F box to the float switches and depth probes.

I never did answer this, so I have put in a proposed labelling scheme below.

Lady_Hanham_Connector_Annotated_Layout.jpg (80.51 KiB) Viewed 1248 times

Obviously, we could cut-down the amount of information on the labels if space proves to be at a premium, but that seems a reasonable approach to me. what do you think?

[TerryJC]

I believe that there's been a colour change in the wiring for the Composite Float Switch. Previously, the colours were:

• Max - Orange.
• Min - Brown.
• Com - Blue.

The supplied cables and internal wiring use different colours, so I am wiring to the following scheme:

• Max - Yellow.
• Min - Green.
• Com - Black.

Penri,

Am I correct that the earlier Float Switches used the original colours? If so, I'll put a note in the documentation.

[TerryJC]

The Probes are using the same colours as previously. Do you have the pinouts of the round industrial connectors to hand; ie Probe, Float Switch and Solenoid. I'll add the information to the documentation.

BTW. I only used the red and black wires for the solenoid. We can double up if needed, but if the current is only around 300 mA, it shouldn't be necessary.

[TerryJC]

BTW. I only used the red and black wires for the solenoid. We can double up if needed, but if the current is only around 300 mA, it shouldn't be necessary.

Using a 16 Ohm Load (approx 750 mA) in conjunction with the cable that you provided (which is very long), I lose almost 1 V at the load. With a 300 mA load, (which I don't have to hand), we should lose less than half that.

Penri, Can you check if the solenoid operates with only 11 to 11.5 V across it? If it's not reliable, I may have to double up (although the cable may end up considerably shorter anyway).

[Penri]

Hello

Just seen the questions, the notifications for your (Terry) posts are not getting to me but Hamish’s did! I can’t answer right now but will do so later.

Penri

[Penri]

Hello

OK, here are the questions and, I hope, the answers:

I'm assuming that the patch panel is being used to make it easier to make-off the ends of the incoming Cat 5 Ethernet cable, as with the Wendy box. I note in the finished version that the patch panel currently has three cables terminated on it, all coming from the three Ethernet cables which emerge from the cable gland that you labelled 'Ethernet links to Gate Valves'. There is currently no Cat 5 cable from the 'backbone' (of course), but the gland that you labelled 'Ethernet backbone I/O currently carries the big blue 12 V cable that splits into three for the Gate Valves. From this I assume that the incoming Ethernet backbone will now use the vacated '12 V DC Out' gland.

I like to use patch panels, when they're available in these boxes, because I think one (me) can make a more reliable connection using them.
I have run another Cat 5e cable from the Railway room for connection to the patch panel in this box (completed today) and will then either cut the existing link to the Reception router and terminate in the Patch panel or run another Cat 5e cable in parallel to the Reception Router for later connection. This may sound a convoluted way of going about things but as I'm helping to run new CCTV cables along the same route dropping in a new Ethernet is no big deal. Running a parallel Cat 5 into reception will mean that we can use the existing cable when WMT re-opens should I fail to get everything finished on time and we can make the switch over at our leisure.
I should have labelled the glands before using them, but got carried away using whatever one seemed right at the time of wiring, so yes you are right the incoming/outgoing Ethernet backbone will use the '12 V DC Out' gland.

The incoming Ethernet backbone will therefore also go to the patch panel, which will then link everything to the Switch. Did you intend that the Lady Hanham SAC Ethernet cable would plug directly into the Switch or go via the patch panel? The former is simpler, but the latter means that everything will be labelled.

My preference would be to go via the patch panel.

I believe that there's been a colour change in the wiring for the Composite Float Switch. Previously, the colours were:
Max - Orange.
Min - Brown.
Com - Blue.
The supplied cables and internal wiring use different colours, so I am wiring to the following scheme:
Max - Yellow.
Min - Green.
Com - Black.
Penri,

Am I correct that the earlier Float Switches used the original colours? If so, I'll put a note in the documentation.

The wire colours used within the Max/Min Float assembly itself are still Orange, Brown and Blue but I could not source a multi-core cable with those colours to make us the cable forms, so had to “improvise” with what was available. As it happens you have make the same choices as I did, which is perfect!


Connector Pin outs.
Depth probe:
1 - Red - 12V
2 - Black - 0V
5 - Brown - x00mm
8 - Violet - x75mm
10 - Yellow - x50mm
12 - White - x25mm

Max/Min Float switch
1 - Common - In cable Black - On assembly Blue
2 - Min - In cable Green - On assembly Orange
3 - Max - In cable Yellow - On assembly Brown

Solenoid
1 - Red - 12V (Switched)
2 - Black - 0V
4 - Yellow - Spare
5 - Green/Blue - Spare

I hope that all OK and understandable,


Penri

[Penri]

Terry

Realised I missed this question:

Using a 16 Ohm Load (approx 750 mA) in conjunction with the cable that you provided (which is very long), I lose almost 1 V at the load. With a 300 mA load, (which I don't have to hand), we should lose less than half that.

Penri, Can you check if the solenoid operates with only 11 to 11.5 V across it? If it's not reliable, I may have to double up (although the cable may end up considerably shorter anyway).

I need to check this out, the new 4 core I purchased is less meaty than it's predecessor so doubling up would probably be a good idea, but I'll check and report back. Please bear in mind I'll be testing the solenoid valve dry! at least to start with.

Penri

[TerryJC]

I need to check this out, the new 4 core I purchased is less meaty than it's predecessor so doubling up would probably be a good idea, but I'll check and report back. Please bear in mind I'll be testing the solenoid valve dry! at least to start with.

Yes. I found out that the cable was less meaty; a couple of wires broke off at the back of the connector for the G1 Float Switch. The break was where the tag meets the insulation and presumable occurred when I was stretching the cable to connect the other ends to the Terminal Board. Not a major problem, since once the Box is installed it shouldn't experience any more physical stress.

I think I'll double up anyway because your point about testing the valve dry is a good one. I would have thought that there will be some headroom, but we can't rely on that because most users (in ponds, fountains, etc) would probably use mains-type wire rather than equipment wire, so the manufacturer would assume very little volt-drop.

Thanks for the responses to my queries above.

[Penri]

Terry

A thought just occurred to me.

I had it in my mind to cut the current Ethernet link between the Reception router and the Railway Room in order to take it through the Hanham patch panel / switch, do I need to do that? Is there enough capacity in the Railway Room switch to allow us to connect the Hanham switch directly to it, If so is that desirable? It would mean that the Hanham box can be bought on line without disturbing the integrity of the rest of the network.

See diagram attached.

Hanham network switch.odg

(50.88 KiB) Downloaded 77 times

Penri