Printronix ThermaLine Series - Manual (Page 341)

8–9 Error Codes
46 ALPHA X expansion HE and Y expansion VE must be zero
When the expanded character parameters VE and HE are used within the
ALPHA command, both values must be either zero or non–zero values. If the
elongated characters parameter [E] or the compressed characters parameter
[Cn] is used in the ALPHA command, the VE and HE values must be set to
0.
47 ALPHA X expansion factor HE out of bounds (> 139)
The horizontal expansion factor is greater than 139.
48 ALPHA Y expansion factor VE out of bounds (> 139)
The vertical expansion factor is greater than 139.
49 Compression Cn or Density error (10, 10A, 10B, 12, 13, 15, 17, 20)
The optional compression parameter (Cn) which defines the horizontal pitch
of the text was specified incorrectly. The pitches currently available are 10,
10A, 10B, 12, 13, 15, 17, and 20 cpi.