The REQUEST statement sends a Service Request (SRQ) on the IEEE-488 bus. You specify either an interface select code or an I/O Path and a service value. To request service, the response value must have bit six set. The SRQ line will remain set until polled by the active controller or another REQUEST statement is executed with bit six clear. For example:
REQUEST 7;Bit3+Bit4+Bit6
If the computer is the active controller or if the device-selector or the I/O Path specifies address information, an error is generated.
