ASYNC GETMODEMOUTPUT: Difference between revisions
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If a general failure error is not returned, the physical device driver returns the current modem control output signals of the COM device. | If a general failure error is not returned, the physical device driver returns the current modem control output signals of the COM device. | ||
[[Category:IOCtl | [[Category:IOCtl Function]] | ||
Latest revision as of 18:58, 22 October 2021
Returns the modem control output signals.
- Category
- IOCTL_ASYNC (01h)
- Function
- ASYNC_GETMODEMOUTPUT (66h)
Parameter Packet Format
None. Packet pointer must be NULL.
Data Packet Format
| Field | Length | C Datatype |
|---|---|---|
| Modem Control Output Status | BYTE | UCHAR |
- Modem Control Output Status
- If a bit has a value of 1, the condition is on. If a bit has a value of 0, the condition is off.
- Bit 0: Data Terminal Ready (DTR)
- Bit 1: Request To Send (RTS)
- Bits 2-7: Undefined
Returns
If the call is made with an invalid Parameter Packet value, a general failure error is reported and valid information is not returned in the Data Packet.
Remarks
If a general failure error is not returned, the physical device driver returns the current modem control output signals of the COM device.