National Instruments GPIB-COM - Manual (Page 36)

Section Five Programming the GPIB-COM
© National Instruments Corporation 5-9 GPIB-COM User Manual
Bit Mnemonic Description
3r/w PEN Parity Enable Bit
If this bit is set, the INS8250 will generate and check parity
according to the values of the STP and EVEN bits (bits 4 and
5). If this bit is clear, the INS8250 will not generate or check
parity bits.
This bit is ignored by the GPIB-COM.
2r/w STB Stop Bit Control Bit
This bit controls the number of stop bits sent and verified by the
INS8250. If this bit is set, two stop bits will be used. If this bit
is clear, one stop bit will be used.
This bit is ignored by the GPIB-COM.
1-0r/w WL[1-0] Word Length Select Bits
These two bits set the length of the words sent or received
according to Table 5-3.
Table 5-3. Word Length Select Bits
Bit 1 Bit 0 Word Length
0 0 5 bits
0 1 6 bits
1 0 7 bits
1 1 8 bits
These bits have no meaning on the GPIB and are ignored by the
GPIB-COM circuitry.