Your comments

Next IQAN Creative Studio training in Mölnlycke moved to 6-8 of October.
I think that a function like this could be useful. There is a similar idea about a quick way of modifying channels that in a discussion here:
http://forum.iqan.se/topic/676587-ability-to-change-logic-function-block-quickly-by-drop-down-box/

Hello Raúl,

Are you using an MD4 build during 2014?
The first IQAN-MD4:s had a quite short RTC backup time, about 4 hours.
I am not sure if you saw this, but on MD4:s built 2015 the RTC backup time has been increased to 14 days.



There is still no battery inside, but a RTC with lower current consumption than the first MD4:s. This is supplied with a capacitor inside the MD4. It gets charged either if you connect +BAT or +RTC.
Hi Zach,

The XT2 is not in phase-out yet, but it is getting old so it is a very relevant question.

The way I see it, the XT2 has got three unique features:

-E-gas servo output (H-bridge).
The E-gas servo output is still being used in some applications with smaller engines where there is no J1939 interface.
You can build this using a pair of PWM outputs on e.g. an MC2, but it is easier to use an XT2.
-High frequency based COUT with sinusoidal ripple
The XT2 COUT has traditionally been used on hydtrostatic transmissions where there needs to be a very smooth ripple. But nowdays most of the applications I see just use a regular COUT:s on MC2 or XA2 with an increased PWM frequency for driving the hydrostatic pumps.
-J1939 gateway
In the days of the MDM and the IQANdevelop system, the XT2 had to be used as J1939 gateway.
Now on the IQANdesign platform where all master modules have two to four CAN buses, this gateway function on the XT2 is very rarely being used.
Also, you can mix J1939 traffic and IQAN expansion bus traffic on the same physical bus, so even if you are running low on CAN buses on your master, you don't need to use the XT2.
Compared to mixing IQAN expansion modules and J1939, and using an XT2, the bus utilization on the IQAN expansion bus would be almost the same, since all J1939 data that passes through the XT2 must run on that bus also.
A drawback of using the XT2 as J1939 gateway is that there are fixed limits on number of PGN:s it can handle, and it does not support all features, e.g. DM2 viewing.

In general, I would not recommend designing a new system with the XT2 as J1939 gateway, it is almost always better to connect the J1939 bus on the master module(s)


Hi Graham,
If you are controlling a solenoid valve, then it is only the current you will need to control. With the peak current being 780mA, you should be within the range of what you can drive with an IQAN-MC2 COUT.

The COUT is driving a current using a PWM. During the on-phase, the switch is open and you will have a voltage just below the +BAT level. The COUT measures the current, and regulates it by varying the pulse-width. This means that you will get the commanded current even when the supply voltage and load resistance varies. As long as you are not limited by the law of Ohm of course.

So if you set your max current to 780 mA, you should be able to drive this current, assuming that you have sufficient supply voltage to the MC2.
For a system with a non-touch MD4-5 the idea with a system information channel from the MD4-7 that reads the actual backlight setting is interesting.

You could of course use a slider on a display page for a parameter that controls the backlight of the MD4-7, and send this paramer to the MD4-5-T0, but it seems as if you already figured this out. The drawback of this is that when adjusting from the built-in menu system, the backlight parameter does not get updated.


The parameter "J1939 error check" will have two effects if the parameter is outside the data range (bit value above >250 for a 1 byte parameter)
The channel status will change from OK to error, and the channel value will become the Error value defined on the JPIN.
The error status will also be logged in the system log.

Below is a printrsceen from a simulation, in the IQANsimulate window on top the raw value is shown (254), and in the IQANdesign window, the channel value is shown, here it is 0°C, the error value defined on the JPIN.


If you set J1939 error check to No, the JPIN will not consider the value 254 to be an error, and instead use the value sent out to calculate a temperature that is outside of the data range for Engine coolant temperature (-40 to 210 °C). The JPIN would get the value 214°C.



Since there is conflicting information about the priority, I would recommend setting Priority to don't care. That way you can use the same application for both the priority 3 and priority 6 variants.