I solved the problem by using a ViewMarq Marquee and writing the ascii string to an OPC tag in Ignition. A gateway script would poll tags in Ignition to gather the information. The gateway script would then assemble the ascii string in accordance with what the ViewMarq would expect. Teh gateway scripts would update the OPC tags that were addressed to the holding registers in the ViewMarq resulting in the message displaying.
One pitfall is that the ViewMarq would only take 150 characters therefore I would have to write to 3 OPC tags to create the entire 450 character message. Also, each string had to be an exact length to work therefore I would have to pad the strings with spaces as needed. Python string manipulation worked for this.