Functioning Serial Ports on New Laptops

This is a major problem in our plant. We have 3 elec engineers and about 12 technicians, and we are all struggling, each in his own way, with getting reliable serial communication ports working on our newer laptops.

I have read the threads in this forum, and they have been very helpful. But it seems to me we aren't really addressing the problem from a TECHNICAL standpoint.

Some advise "Only purchase a laptop with a REAL serial port..." (getting to be pretty scarce). Others have listed certain USB->Serial converters and PCMCIA serial cards that have worked well for them. I started off using this advice, bought some devices, and thought I was in good shape. But with the passing of time I am convinced that NONE of these devices are a complete answer. They work with one laptop but not another, they work with this PLC but not that one. They work on Tuesday but not on Wednesday!

I'm sure a big part of the problem is we have NEW laptops running (or trying, at least) OLD software. And when we cannot establish serial communications, we have too many links in the chain! Is it
1)the serial cable? 2)the converter? 3)the operating system? 4)the service pack? 5)the upgrade level? 6)the firewall settings? 7)the port settings 8) a conflict with another device? 9)the old software?

(Just 5 minutes ago, a technician told me he got the serial port on a new laptop working by turning off the service for the wireless ethernet port!!?)

What we need to achieve in some way, using a combination of hardware and software, is a highly dependable and completely robust way to setup, verify, test and troubleshoot serial connections. Instead of groping in the dark when it doesn't work, we need to be able to grab our "toolbox" and fix it. Like maybe a "wizard" to walk through a computer and setup everything needed to make a serial connection work. And maybe it could test it and report where and why it was failing.

So what do you think? Is this too much for a bunch of highly intelligent, well-trained technical folks to come up with? :nodi:

A loopback tester and Hyper terminal.
http://zone.ni.com/devzone/conceptd.nsf/webmain/D48BA43C59B60277862569EE000501FD?opendocument

There is also software available that can do alot of diagnositcs. This company has an evaluation version and sells the loopback connectors.
http://www.passmark.com/products/bit.htm

I know such problems and we figured out that the serial port via USB works if you first connect your PLC to the USB adapter and than at last you plug your USB adapter in your PC. Hopefully it helps.

It is time to ditch the serial port.

Foghorn22 said:

What we need to achieve in some way, using a combination of hardware and software, is a highly dependable and completely robust way to setup, verify, test and troubleshoot serial connections. Instead of groping in the dark when it doesn't work, we need to be able to grab our "toolbox" and fix it. Like maybe a "wizard" to walk through a computer and setup everything needed to make a serial connection work. And maybe it could test it and report where and why it was failing.

Click to expand...

We all know that RS-232 ports on laptops are becoming rare and cables non standard. My attitude has been to stop crying about it and only by laptops with a RS232 port. However, my favorite options for wide or big screen laptops are losing their serial ports. ( In my opinion and laptop must have the biggest screen possible for efficient programming ). Quatech PCMCIA cards work well with most applications but not everyone is going to be happy spending another $150-$200 on a PCMCIA card just to accessing RS232 which we used to do for free. In addition to that there are some protocols such as Modbus RTU that are very timing dependent and will not work through a RS232 to USB converter. Finally, many PCs and laptops drop too many packets because of WINDOZE operating system. Troubler shooting USB to RS-232 adapters will always be a problem because of the items listed above.

We are replacing the RS232 port on our latest product with USB port. Hopefully this should make accessing our product easier. The problem with USB is that it really isn't industrial strength, but it will be easier to use. So far the USB look reliable and offers an easy way for one PC or laptop to talk to many of our products. For serious work there is always the Ethernet port. Is 5 meters long enough? I don't think so.

What we have found out so far is that USB to an industrial device works as a replacement for RS232 but it isn't as fast as one would expect but it is faster than a RS232 port. We are actually sending DF1 over the USB cable and treating the USB as if it is a fast serial port. The down side is that HMIs don't have USB yet and a driver must be installed. The good new is that these guys have made it easy by providing free drivers for their chips.

http://www.ftdichip.com/

The market place will tell us whether we are right or wrong.
It is the only poll that really counts. I will let you know how it is working out.

BTW, if you must by a Quatech card then consider getting a RS485 card so you can run some distance and talk to multiple devices.

The down side is that HMIs don't have USB yet and a driver must be installed.

Click to expand...

Omron NS screens do have them but, at the moment, they are just used for printers (USB host).

However, my favorite options for wide or big screen laptops are losing their serial ports.

Click to expand...

HP/Compaq still have real serial ports in many of their laptops. I have just purchased one. Check the model as some do not.

Just 5 minutes ago, a technician told me he got the serial port on a new laptop working by turning off the service for the wireless ethernet port!!?)

Click to expand...

Not surprised. With my last laptop I had to turn off the modem whenever not in use as the software used to pick up the modem as a serial port. Took a while to find that one!!!

I would suggest you try turning off modems, and any other communications ports and try that. It may be the answer you are seeking.

i set up a door access system in a plant a while back..they wanted a new computer for the system (Its dedicated for that) so when i upgraded the software into the new puter i had problems..becouse of no serial port..I got a USB to serial and it works...For a while..becouse this puter sends and recives data constantly the port only works for about 2-3 days then the IRQ seems to "wander" and i loose all comms. The only way to fix it is shut down, restart and then reset all the programs..(the programs automatically shut there comm's after x amount of time if not talking to anything..I think it does it becouse otherwise it would fill the hard drive with nothing but comm errors, (It polls the device about 2 times every second and logs everything it gets back..even comm errors)) I would love it if someone came up with a reliable replacement for 232 thru USB...

Also could be wrong but i think i saw USB on a panelview + terminal??

D

As an FYI timing issues with RS232 has nothing to do with Windows, its ACPI (advanced configuration and power interface) that creates the problems.
What is ACPI: http://www.webopedia.com/TERM/A/ACPI.html

http://developer.intel.com/technology/iapc/acpi/faq.htm

Its possible to disable ACPI and return to the old Plug and Pray standard, in many cases this will eliminate issues with serial ports. It may create other issues though.

ACPI can also create issues with IRQ steering which is why an IRQ seems to "wander".

Some of the PV+ do have USB: http://www.ab.com/en/epub/catalogs/12762/2181376/1239781/1618383/

I looked at Panasonics's toughbook line of hardened PCs - they had a booth at the Manufacturing Show in Chicago a couple weeks ago.

About 2/3 of the models on the floor had serial ports.

http://www.panasonic.com/computer/toughbook/home.asp

These laptops are not inexpensive, by any means. In fact, $170 for a PCMCIA serial adapter added to a standard business laptop is probably less expensive than a toughbook, but Panasonic does some engineering to harden their toughbooks.

Dan

I know this doesn't help, but the thing that really burns me is that they still leave on the sodding great parallel printer port that no-one uses any more because most printers are either USB or networked these days (at least I haven't plugged anything near the parallel port in about a decade).

Come to think of it...has`anyone had any success with a parallel to serial port converter as an alternative to the USB or PCMIA devices?

Most Laptop manufacturers build a device called a port replicator. This will extend the bus and provide a REAL serial port. They usually run about $70 to $90.

skalt said:

Most Laptop manufacturers build a device called a port replicator. This will extend the bus and provide a REAL serial port. They usually run about $70 to $90.

Click to expand...

Isn't a port replicator a big plastic thingie that sits on the CEO's desk that he plugs his laptop into?

Are port replicators at all portable, so it can be taken on the shop floor?

Dan

rsdoran said:

As an FYI timing issues with RS232 has nothing to do with Windows, its ACPI (advanced configuration and power interface) that creates the problems.
What is ACPI: http://www.webopedia.com/TERM/A/ACPI.html

http://developer.intel.com/technology/iapc/acpi/faq.htm

Its possible to disable ACPI and return to the old Plug and Pray standard, in many cases this will eliminate issues with serial ports. It may create other issues though.

ACPI can also create issues with IRQ steering which is why an IRQ seems to "wander".

Some of the PV+ do have USB: http://www.ab.com/en/epub/catalogs/12762/2181376/1239781/1618383/

Click to expand...

Ron i am am simple guy...could you explain this in simple terms??If you could show me how to fix this i would be eternally gartefull..The customer dosnt like the rebooting and i dont like leaving the job know it isnt right...

Thanks...

That thingie on the CEOs desk is a docking station. A port replicator is similar but smaller.

darren I spilled a "liquid" on my laptop where all my links are, it dont work now. Check back tomorrow and I can provide the info for disabling ACPI.

Got my laptop going again so here are some links that may help. This one is from AB and primarily concerns the PIC driver but it does explain disabling ACPI.
http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/6ead4531e08f2074852569bb007630d5/d55abd27967b45ce85256afb005d52c3?OpenDocument

There is an ACPI website but it wont come up for me.
http://www.acpi.info

NOTE: You can make a copy of current config in Control Panel > System > Hardware tab > Hardware Profiles... this will allow you to choose between Standard PC and ACPI boot.

Make sure when/if you do this you have all drivers and the OS cd. Each computer setup is different so disabling ACPI can create other problems or make everything work perfectly.

FYI: Another issue is "shutdown" problems, the system goes to sleep due to inactivity so devices may be disconnected.

Another FYI is the fact that not all manufacturers follow the Intel ACPI specs so there may be a faulty DSDT, ECDT etc. A google search on ACPI will provide more info on this.

Since each system with windows may have different problems I usually seach the MS KB on the subject.
http://support.microsoft.com/search/?adv=1