Hardware Question:

In the Documentation for the MC4x family of controllers - it says in many places to use diodes for external coil suppression, for example when driving a relay with the Digital Out HS driver from the MC4x.

A relay that I have specific to my application requires (highly recommends) the use of varistor coil suppression, which is less "harsh" on the relay device during transients. The specification requests a clamping voltage of 3x the coil voltage, i.e. 36Vdc for a 12Vdc relay coil.

Are there any adverse affects of using a varistor instead of a diode for coil suppression? 

Perhaps this could be also compatible with the hardware design of the MC4x series of controllers?

(Hint: I already have tested this configuration on my system to many thousands of cycles under load with no discernible affect on system operation or relay operation)

This module supports alot of IO and 5 x CAN. Very simple functions to serve all of the IO and CAN easily burn the available resources and I am wondering if there are any upgrade plans ?

I want to check if there is a benefit to connect the Ethernet ports on MD4 and MC4x with a switch in a Multi-Master layout or to prepare for a coming feature?

I'm hoping someone might be able to chime in if they have seen something similar before.

I'm driving two contactors (they close at different times) off the MC41. The contactors at peak draw 3.9A for about 75ms. When the contactors close, a very short time later, the MC41 enters a critical fault. The flashing lights (4R, 1Y, 12Y, 3Y, 1Y, 2Y) seems to indicate there is a 'watchdog' fault. Looking at my CPU/RAM usage and cycle usage, we are not even using 1% capacity. Is it possible this overcurrent condition could trigger this particular fault?

As well, I can't seem to find any information on what the 12Y is supposed to mean? "R4:1 n:3:1:2" which would be the "n" in the manual. What would the 12th part of the software mean?

Hi!

Previously we used MC2 in a project. Now changed master module in the program to MC43.

We have a DIY test board (large resistors with LED for indication) to double check if the machine sends signal to valves etc.

Using COUT channels...so connectors come in pairs. With MC2 if one of the connectors wasn't connected to a load it would display "open load" error when machine would send a signal to a valve that isn' t connected, but connected one would work when output is signal is given. (no open load error when joystick is in neutral)

Now with MC43- both COUT pair connectors have to be connected for it not to display "open load" error..even when joystick is in neutral position.

Is this because MC43 diagnoses itself differently than MC2 or is there something to be changed in the program?

Hi, I have an issue with intermittent MC43 COUT overload errors on one of our machines.

Status is OK and operates well in most conditions, but will randomly report overload (even when that function is not requested).

I have tested the solenoids, plugs, and wiring harnesses within this circuit and all looks ok.

COUT circuit C1:16, 41, 57.

Is there anything else I should check to see what might be going wrong?

We have a machine that has sporadic nuisance open load errors on a function controlled by a unidirectional current output (COUT-G) on an MC43. Since this happens with some frequency, I suspect we are right up against the limit of the open load detection threshold. They test out well in assembly, but any increase in resistance occurring in the field might be setting it over the edge of the error threshold.

How can I calculate at what load resistance, commanded current, and supply voltage an open load error will occur?

This function is controlled with a Parker CCP024H 1/2" super coil with nominal resistance at room temperature of 30.30 ohms. Machine runs on 24V (around 28V when alternator charging). Maximum commanded current is set to 600mA.

Are the current out channels on an MC43 suitable for dishing out a 4-20 ma signal? It would be controlling a VFD.

I know the current out channels are typically used to control valves and used in the hundreds of milliamp range. 

We are using a MC43 and using PWM and COUT channels. What we have noticed is when a PWM HS output is shorted to ground, one of our COUT outputs goes into overload. In our case, C2:51 was shorted to ground but C2:67/C2:15 had the overload error.