IBM TM7 - Manual (Page 171)

Note: The last valid value is kept when an invalid value is sent.
Print PDF417 Bar Code
RS-232 Syntax:
GS P data NUL or X'1D;50;data;00'
where:
data The ASCII representation of the characters to be printed.
Remarks:
Valid only at the beginning of a line. Printing will not start until a X'00' is
received.
This command will increment status byte 6.
The maximum number of characters to be encoded is 1000.
Error Conditions:
If an image cannot be printed, status byte 7, bit 2 will be set. This may
happen when the image is too big to print. Try decreasing the ECC level.
Select PDF417 ECC (Error Correction Codewords) Level
RS-232 Syntax:
GS R n or X'1D;52;n1;n2'
where:
n1 The high-order byte of the ECC level.
n2 The low-order byte of the ECC level.
Default:
n1 = 00
n2 = 15
Range:
0 ≤ n1n2 ≤ 400 decimal (170 hex)
Remarks:
For 0
≤ n1n2 ≤ 8, the ECC level is assumed as that particular security level.
The security level determines the number of error correction codewords
added to the symbol.
Error Correction
Security Level Codewords
0 0
1 2
2 6
3 14
4 30
5 62
6 126
7 254
8 510
updated March 18, 2002
Appendix C. RS-232 Programming Information 147