Spd; Spe - HP E4418B Programming Manual

IEEE488.2 Command Reference
Universal Commands

SPD

The SPD (Serial Poll Disable) command terminates the serial poll mode for
the power meter and returns it to its normal talker state where device
dependent data is returned rather than the status byte.

SPE

The SPE (Serial Poll Enable) command establishes the serial poll mode for
the power meter. When the power meter is addressed to talk, a single
eight bit status byte is returned (refer to "The Status Byte", on page 1-80
for further information).
15-6 HP E4418B/E4419B Programming Guide