In some situations, you have to reset the parity because the system that you are calling checks port parity and drops the line if it is wrong. The expect-send couplet P_ZERO sets parity to zero:
foo =,-, "" P_ZERO "" \dA\pTE1V1X1Q0S2=255S12=255\r\c OK\r\EATDT\T\r\c CONNECT |
The following are parity couplets that can follow the expect-send couplet:
Sets the parity to even, which is the default
Sets the parity to odd
Sets the parity to one
This pseudo-send string can also be used in entries in the Systems file.