Internet PLC Forum

My issues go beyond Wrte protecting the M2017P

The issue is the loss of the program, due to electrical transients.

I have gone through the excersize to add ing TVS diodes, as well as isolating the T100MD888 using a Dc/Dc converter.

This is a mobile aplication where power is +12 VDC from a vehicle. We have purchased in excess of FORTY T100MD-888+ units, and I buy replacement M2017P's

My ONLY problem is the loss of the program due to some electrical issue ( Load Dump has been mentioned as the culprit). NO OTHER component has failed as much as the M2017P.

Some times I can re program, but other times, the PLC will not communicate to the host PC, and the solution is to replace the M2017P.

So again is it possible to replace the M2017P with a One Time programmable PROM?.

You have no idea how pissed I am about this issue.

Ben

The design requirements for mobile use was underestimated, both electrically and physically.

Vibration is a big issue, with LM7810 regulators breaking off, connectors coming off, MXRTC/SDRAM's coming out of their socket.

We have moved to using tie wraps to hold the MXRTC stack, and Hot melt to stake the connectors, and to connect the regulators to the filter caps ( creating a larger mass)

Now we will progress with the DC/DC converters to see if we can minimize EEPROM failure

Speed is not the issue, reliability of data in the EEPROM is.

I would settle for a OTP 8 pin PROM, if it would solve my constant EEPROM corruption problems. I have 35 PLC's operating in the field with 12 VDC automotive power. I have installed the 1.5KE24A TVS diodes, and I still receive about 4 units a month, for reprogramming of the EEPROM.

Good Morning,

CCdubs, have you been able to solve your problem, I am still having issues with my 12 vdc, driven T100MD888+ mobile units

Thank you

Hi,

I installed the 1.5KE24A transient suppression diodes across the power leads comining into the unit. This is upstream of the steering diode feeding the circuitry.

The remedy is not 100%, I have had units returned from the field, after the diode has been installed, where the M2017P has been corrupted, some to the point of not being able to re-program.

I think your firm should develop a special power conditioner module, to allow relable use of a T100MD888+ in an Automotive application.

Our dealer, DCI Inc. in Calgary Canada,  pointed us to a DC/DC converter that they have been trying, we purchased a few, and are trying them as well, so far no field results. Lab tests have been positive.
We are also going to try the DC UPS from http://www.powerstream.com/DC-UPS-1212.htm and add a Sealed Lead Acid gell cell to the system.

My biggest problem with all of this is that the only item to fail is the M2017P.

Thanks for the info.

Thanks for the info.

Thankyou for your information. I will purchase these "Load Dump protection diodes" , and install them on the power input to the PLC.

The "Motherboard" we use has another linear regulator on it, with appropriate reversed biased diodes for short circuit protection. It appears the T100MD888+ has these as well on the two power regulators at the input to the PLC.

In the 3 years of operation, we have had two op amp failures, and the six M2017P's. There are three Op amps per motherboard. to condition the Analog signals going into the PLC.
This is 2 Op amps out of 78 in use, versus six M2017P out of 26 PLC's.

I have had no other electronic failures of any other IC's on the PLC's, or motherboard.

It is also noted that there are no bypass caps ( .01uf or 0.1 uf ) near the M2017P, and only the 220 uf Aluminum Elctrolytics by the regulators. Alot of designers use tantalum and ceramic bypass caps for transient handling.

In the absence of other failures, it would seem that the M2017P is quite sensitive to something that the other components are not.