Yes, your manual says that the default mode is "Control + ASCII Mode Off". You probably should change it to "Windows Mode Control + ASCII Mode On". Your PLC ARL instruction is looking for the ASCII end-of-line characters (0D0A I think). You have to use whatever Honeywell Xenon Scanner mode will insert those characters at the end of each bar code.
I see that on page 2-2, there is a scan code to set your scanner for "RS232 Serial Port". It has the required ASCII carriage return (OD) and Line Feed (0A) characters. The only problem is that it also sets the baud rate to 115,200 bps. I think you need about 9600.
It appears that you may have to scan-and-save several different codes from the manual to get your scanner set up the way you want. An alternative method is listed on page 10-3, for how to use a EZConfig downloadable software program to more easily set up your Honeywell scanner.