View Full Version : ISaGraf and Dixell

27-06-2012, 09:06 AM
Hi guys,

I'm prepping for a course on ISaGRAF, presented by Dixell for their iPro range of PLCs for refrigeration.

Everything so far seems pretty basic and easy to understand.
I love the flexibility of ISaGRAF being able to add Structured Text and C-code to programs over the very basic proprietary programming software like Crouzet's Millenium software. Double Integers, Long Integers and even Real numbers is such a luxury coming from straight Integer programming.

I have however hit a snag.
I want to create my own custom Function Blocks and add them to the library supplied by Dixell. Unfortunately Dixell has passworded all their custom function blocks, so I can't see inside on how to structure a custom function block in ISaGRAF, and I'm not having any luck finding something online yet.

Can anyone help with just the ST code in a simple custom function block for ISaGRAF?

27-06-2012, 01:07 PM

Finally figured it out...
After the program has been debugged, it can be dragged down to the Function Blocks branch.
All it's variables are then made local.
Short and long descriptions can be added. These are used on the FB itself.
Variables that are supposed to be the inputs and outputs of the FB must have their type changed to reflect this.
The FB can then be used in a FBD, and will display and function properly.
It cannot be debugged anymore, and has to be dragged back up to the Programs branch for any late debugging.

27-06-2012, 07:43 PM
Mate, you may as well be speaking chinese there!! i love how indepth you get with the software, is it for work or for yourself?


install monkey
27-06-2012, 08:16 PM
well al here goes-嗨夥計們,我我上課為 ISaGRAF,其 iPro 製冷可程式設計系列控制器由 Dixell 提交課程。到目前為止,一切都顯得相當基本的和易於理解。我愛 ISaGRAF 能夠將結構化文本和 C 代碼上的非常基本的專有程式設計軟體,像高諾斯的千年軟體添加到程式的靈活性。雙整數、 長整數和甚至實數是來自直整數規劃的這種奢侈。不過,我已經遭遇困難。我想要創建自己的自訂功能塊並將它們添加到由 Dixell 提供的庫。不幸的是 Dixell 有 passworded 他們所有的自訂功能塊,所以不能請內部參閱有關如何在 ISaGRAF,一個自訂功能區塊的結構及我未有任何尚未找到一些線上的運氣。任何人都可以為 ISaGRAF 幫只是一個簡單的自訂功能塊中的 ST 代碼嗎?:D

Mate, you may as well be speaking chinese there!! i love how indepth you get with the software, is it for work or for yourself?


27-06-2012, 09:34 PM
thats much better IM!


28-06-2012, 07:20 AM
Mate, you may as well be speaking chinese there!! i love how indepth you get with the software, is it for work or for yourself?


Hi Al,

It's for work. I'm still very new in the industry (only 3 years now) I've designed my first trailer unit. We have 10 in the field and just completed R&D.

But our current control is kinda limited. And because we're a small company we can't afford a custom built controller like the big guys.
So we use a standard Dixell XR50C that handles temperature regulation and defrost etc., and a standard industrial PLC to manage the package. This is for things like water temp, oil pressure, diesel start sequence, HP, LP, Fans on/off, valves, throttling etc etc...

But now with Dixell's iPro range of PLCs we can incorporate those 2 into a single unit, and get so much more. Many more analogue inputs. Analogue outputs. Our software will now actually know what the temp probes are reading etc etc.
We're also looking at incorporating some other technologies on our next unit.
Our current unit is kinda a hybrid. Diesel engine turning a compressor directly, with a belt drive up to an alternator. The alternator only supplies power to our fans. It's a reasonably flexible system, but still has drawbacks. Thermoking is launching their unit of similar concept next year.
By then we want to be one step ahead again.
Semi-hermetic compressor, full vari-speed drives on everything, smaller engine, large COP, Electronic expansion valve, full man-machine-interface, no throttling, user selectable capacity etc etc.

And that's where ISaGRAF and the Dixell iPro PLCs come in.
I've written a couple of small Function Blocks so far, and this platform is so damned powerful!
I can now take a 0-10 volt pressure transducer. Connect that to an input of the PLC and convert that value to a proper pressure, like in Bar for instance. This has never been a problem on our current system.

But now I can take that pressure and stick it into a formula like
-3.4486e-19 * (pressure)^4 + 2.6257e-13 * (pressure)^3 - 7.4166e-8 * (pressure)^2 + 0.011425 * (pressure) + 172.46 -600
and get a temperature (x10) value out in degrees C. I can properly calculate 4th order curves.

This opens up a world of possibilities for me!
I can measure sub-cooling, and actually know the charge state of my machine.
I can compare the Evaporation temp with the air-on and air-off temps and know the frost state of my coil.
I can compare condensing temp with ambient temp, and know if my condenser is performing to spec.
I can stick evaporating temp and condensing temps into another formula (compressor table) and know exactly what my compressor is doing, and what COP I'm running at.

Yes, it's for work, and I'm as excited as a 4 yr old at Christmas about this!!!!!!

18-07-2012, 11:59 AM
I work with isagraf to . I find it to crash and be slower than i want to click . I have to reinstall it every few months because it keeps crashing.

The system i work with is an advanced package unit . its already designed down to the T by a massive company.

I have to upgrade the software and kernels on the plcs every few years.

Its good for fault finding using the alarms . Im self thought , pretty much was told heres a laptop and heres to program figure out how it works and fix the air cons. so im not to sure about the advance things your talking about but it sounds interesting .
Our system has sensors and extra things everywhere .

18-07-2012, 06:30 PM

Now it makes sense!! I love the Dixell system, i deal with a company in dublin (Frigotech) who have been using them for years, if ever you are stuck on an application they may be able to help. The software program you are using, is it from Dixell?


19-07-2012, 07:03 AM
The software program you are using, is it from Dixell?

Yes, and no.

No, ISaGRAF is development software by a third party.
Yes, Dixell PLCs can only be programmed with ISaGRAF, and Dixell is coming to our factory to present the course on ISaGRAF. This is because Dixell supplies a set of libraries that hook into ISaGRAF, to enable us to use ISaGRAF to program Dixell PLCs.