RQS Status Condition

RQS appears in the status word only after a device-level call and indicates that the device is requesting service. RQS is set when one or more positive serial poll response bytes have been received from the device. A positive serial poll response byte always has bit 6 asserted. Automatic serial polling must be enabled (it is enabled by default) for RQS to automatically appear in Ibsta. You can also wait for a device to request service regardless of the state of automatic serial polling by calling ibwait with a mask that contains RQS. Do not issue an ibwait on RQS for a device that does not respond to serial polls. Use ibrsp to acquire the serial poll response byte that was received. RQS is cleared when all of the stored serial poll response bytes have been reported to you through the ibrsp function.

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