OSTC cR + hw HUD S8

[petkozaric]

Hello,

Please could you inform us little bit more about this package and how we can connect OSTC cR + hw HUS S8 together on 3 oxygen sensor?

We need this kind of design, computer + HUD to control mCCR.

Do you have a wiring diagram? It will be very helpful.

user manual
"1. S8 connector
With the S8 connector you can connect di-
rectly up to three oxygen sensors to your
OSTC cR. Optionally you can use a digital
connection via the hw HUD S8.
The S8 connector is triple O-ring sealed.
This construction is very robust. The OSTC
cR can be connected to standard oxygen
sensors with a common ground.
Before attaching the sensors the first time,
pay attention to the correct configuration
of the pins. The S8 connector has the fol-
lowing pin configuration:
• Pin G: ground, sensor 1,2 and 3
• Pin 1: plus, sensor 1
• Pin 2: plus, sensor 2
• Pin 3: plus, sensor 3
The maximum sensor voltage is 165mV per
sensor.
The minimum voltage for calibration is
7 mV in air (21% O2) and 36 mV in pure ox
-
ygen (100% O2).
The products of heinrichs weikamp use a
100 kOhms load resistor for analog O2 cell
inputs.
The remaining four pins are designated for
the USB connection. Only use the included
original cable! Via USB you can recharge the
OSTC cR and connect it to a PC or notebook
to read logbook data and install updates.
Caution
A dive with an open S8 connector can irre-
parably damage the OSTC cR. If no S8 cable
is connected, always close the socket with
the cap. "

many thanks
BR
Petko

[Ralph]

Well, when using the cR you do not need the HUS as the cR can directly read the analog voltages of up the 3 cells. The cR comes with a S8 cable, i.e. a cable with a connector mating the cR on the one side and an open end on the other side. Wiring is easy: out of the 8 wires in total, four are for USB and you do not need them. Just cut them, I cut them to varying lengths so that they can not make contact with each other. The remaining 4 wires are the common GND for all sensors and one wire for the plus pole of each sensor. So you need to excerceise your soldering iron a bit to hook all minus together and make connection between the plus pairs from the cable and the cells. Put some heat shrink tube above everything, best is to use tubbing with glue on the inside as it gives true watertight sealing. The cR also comes with a cable glant to route the cable through the canister bulkead etc. If you need adapters, either mechanical ones to tab into the breathing hoses or electrical ones like for the coax plugs, company 'narked at 90' provides a lot of those.

BR
Ralph

[petkozaric]

Hi Ralph,

I would like to have a HUD across the computer for mCCR.
In that case how to connect a OSTC cR, HUD and cells all together?

Does It works independent, in case of computer failure?
What is the procedure of calibration with HUD?


thanks Ralph for your time.
BR
Petko

[Ralph]

Is your motivation for the HUD based on its visual indication? To me, that would be the only reason for adding a HUD. The HUD has a battery of its own, the sensors will be attached to the HUD and there is another cable that runs a digital data transfer between the HUD and the cR. The HUD sends the sensor data to the cR and the cR sends calibartion command and the selected setpoint to the HUD such that it can give indication of ppO2 is above or below. There is a manual of the HUD out somewhere....ah look here: http://forum.heinrichsweikamp.com/read.php?6,18135 As you can read in the manual, the HUD is an older product that was made for the discontinued DR5 computer. It is still supported by the cR, but honestly if you are not really after the visual indication it provides, it just adds extra complexity and clutter when used in combination with the cR.

-R.

[petkozaric]

My thoughts going in direction two directions.

1. Fisrt is to have redundant independent (stand alone) device which could reading pO2 from all 3 cells. In case of failure one of the pO2 reading device, dive computer ostc cR or HUD on the other side.

2. The other reason of HUD would be a quick reaction in the event if Po2 falls or rises.

[Ralph]

ok,

1) if using the HUD in the "normal" way, the oxy cells are just read by the HUD and the cR receives it data from the HUD. So in fact, you are not adding redundancy with the HUD but instead extra complexity / points of potential failure. If you are after redundency, you need an independent device directly attached in parallel to the oxy cells. This could be a second cR or any other submersible ppO2 meter out there in the world. With the cR it is no problem to hook it in parallel to some other device, i have mine connected in parallel to my AP Inspiration head electronics - no infuence on readings.

2) As a responsible diver, this calls for some near-eyes indication, i.e. a head-up display of any brand. Well, knowing that some popular eCCR are operated with wrist computers only, but mCCR does call for more caution.

[petkozaric]

thank you for useful information.

BR
Petko