Applies To:
  • CitectSCADA 4.x

There is no activity when trying to print in real time to a printer device using DevWriteLn() function to send text to a local printer. I am able to print from Windows applications and also able to do a screen dump with Winprint("LPT1:",0,0,""). The 'Print Test Page' also works in NT. 

For a Device configured as Filename "LPT1.DOS" and Type "ASCII", there are two things to check;

1. There must be a Format specified for the device or NO data will be output to the printer.

For example to output a line of text up to 132 characters you may specify a format like; {text,132}

2. Try selecting the "RAW" data type from the 'Print Processor....' selection button for that printer's profile:

Windows NT uses print processors to interpret what type of data is being passed from the spooler to the graphics engine. Windows NT defines a number of data types (for example, RAW, RAW [FF Appended], RAW [FFAuto], TEXT, and NT JNL 1.000) to implement print job alterations.

Raw files need no processing from the print processor.

The NT JNL 1.000 (or NT EMF 1.003) data type indicates that the job is being sent from a Windows-based application and uses GDI commands to describe the output while the TEXT datatype indicates that the job consists of ANSI text.

A Device configured as Filename "LPT1:" and Type "Printer_Dev" will not print line by line in real time.