I'm attempting to write a program (or even a set of ZPL commands) to set variables on printers before shipping to clients.

Unfortunately I'm not seeing the "! U1 setvar "wlan.essid" "arbitrary" ZPL command work reliably, nor does it work if I use (C# .NET).  The example below has try/catch and other safety measures removed for brevity:

...
printerConnection = new DriverPrinterConnection("ZDesigner ZQ620 (CPCL)");

printerConnection.Open();

ZebraPrinter genericPrinter = ZebraPrinterFactory.GetInstance(printerConnection);
ZebraPrinterLinkOs printer = ZebraPrinterFactory.CreateLinkOsPrinter(genericPrinter);
printer.SetSetting("wlan.essid", "arbitrary");

I'm seeing *better* results if I try multiple times in ZPL (a recommendation from an associate who'd spoken with a Zebra rep a year or two ago).  I hoped to use the c# code as a hack to try multiple times, and then verify with printer.GetSettingValue(), but I'm not seeing updated values, even if they're present when using the Zebra Setup Utility to view the variables after the program has run.

I'm using a USB connection for sending the commands.  This is the most simplified example, I'm actually setting several variables, and which ones "take" are incinsistant.

Any thoughts?

Chuck