Datamax & Zebra Printers – Network Issues

Earlier this year, I had written about the problems with Datamax printers disappearing from the network when attempting to send them label data to print.

At the time, Datamax had just released new firmware for their printer models that was supposed to fix the issue.

Did it work? Maybe it did to some extent, but many customers (including ourselves) have continued to find that Datamax printers have a tendency to go offline, right when they are needed. Quite often the only solution seems to be to reboot the printer in order to get the connectivity back.

Many of these issues seem to happen to clients using DHCP when the printer has been sitting idle for a while – seems that the printer’s IP address might have been re-allocated to another network device while the machine was idle. This also happens with printers using fixed IP addresses as well – which is the case with out own network. In our label print room, we have several printers and a couple of PCs,ll connected with a simple hub, all with fixed IP addresses. Our printers (I-Class and H-Class models) all have the current firmware installed.

I was thinking about this today because one of our clients was having the old “falling off the network” issue and Gary the Label Guy got some info from Datamax Tech Support that might help.

It was suggested that in the network settings for the printer, the Gratuitous ARP setting be changed from “Disabled” to “Every Minute”.

One reason this got me interested is that I’m not a network guy and I had so idea what “Gratuitous ARP” was. This led is to use the browser on one of our computers to browse into an H-Class printer and take a look:

Gratuitous ARP Setting - Datamax
Here is part of the online setting page for the printer and I’ve marked the Gratuitous ARP setting in red. As you can see, we have set the value to “every minute” as suggested. Did it work? Too soon to say since we have not needed to use that particular machine today. I’ll update this post with the results once we get some run time.

If nothing else, I have learned a little about Gratuitous ARP and what it is all about. For a start, ARP stands for Address Resolution Protocol and the Gratuitous bit is that the device sends a piece of data without being asked first.

In my rather simple way, I’m thinking of it meaning that the printer reminds other devices on the network that is is actually still around, even if it hasn’t been doing any work for a while. This keeps the connection alive and increases the chance of things actually working when another device on the network sends some label data to the printer.

I also did a little Google research on the Datamax network problem and found several forums where users have been fighting the issue. A System Admin on a Meditech Google Group said he had gotten his printers working OK by using the Gratuitous ARP setting and by changing the port from 9100 to 515 – I’ve highlighted that setting with blue in the screenshot, in case you are tempted to try it out.

If you use Datamax printers on your network have you run into this problem? How did you fix it? If you are the IT guy, does this additional data flying around your network cause you any concern? Post your experience in the comments if you have a few minutes!

*Update* Although it is still pretty soon after making the change, I’ve been using our three printers for a while and have had no problem after setting the APR. Maybe it is the solution?

*Update 2* Although setting the APR seemed to work for a while, one of our clients told us that the problem still occurred from time to time. The problem was finally fixed by swapping out the firmware to the latest version. The tech support guy at the manufacturer told us that some changes to fix the network issue had been included in the new release.

*Update 3 – Zebra* We’ve ran into this issue with Zebra printers recently as well. Again the manufacturer tech support told us to set the APR. I’ll report back if it works.

Zebra Gratuitous ARPBest way to do this on a Zebra is to browse to the printer’s web page and click to “Print Server Settings”. Browse to “Print Server” than “TCP/IP Configuration”.

See the screen shot that shows the field for the setting.

From the Zebra documentation, these problems can arise with both Ethernet and wireless networks, so it is good to have this setting info available in case it is ever needed.

Both Zebra and Datamax tell us that using Gratuitous ARP shouldn’t add enough traffic to the networks to cause any issues.

Whatever brand of label printer you have, it is always a good idea to have it covered by a Winco ID service plan so that our technicians can help out.

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