1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465
|
.\" Use -ms and macros.t
.EH ''''
.OH ''''
.EF ''''
.OF ''''
.ps 10
.nr PS 10
\&
.sp 8
.ce 1
\s+2\fBX Display Power Management Signaling (DPMS) Extension\fP\s-2
.sp
.ce 1
\s+1\fBProtocol Specification\fP\s-1
.sp 3
.ce 3
Version 1.0
X Project Team Standard
X Version 11, Release 6.8
.sp 6
.ce 4
Rob Lembree
\fIlembree@zk3.dec.com\fP
.sp 6p
Digital Equipment Corporation
.sp 6p
24 April 1996
.ps 9
.nr PS 9
.sp 8
.LP
.bp
.sp 15
Copyright \(co Digital Equipment Corporation, 1996
.LP
Permission to use, copy, modify, distribute, and sell this
documentation for any purpose is hereby granted without fee,
provided that the above copyright notice and this permission
notice appear in all copies. Digital Equipment Corporation
makes no representations about the suitability for any purpose
of the information in this document. This documentation is
provided ``as is'' without express or implied warranty.
.LP
.ps 10
.nr PS 10
.bp 1
.EH '\fBDisplay Power Management Signaling (DPMS) Extension\fP'
.OH '\fBDisplay Power Management Signaling (DPMS) Extension\fP'
.EF ''\fB % \fP''
.OF ''\fB % \fP''
.NH 1
Overview
.LP
This extension provides X Protocol control over the VESA Display
Power Management Signaling (DPMS) characteristics of video boards
under control of the X Window System.
.FS
1. \fIX Window System\fP is a trademark of The Open Group.
.FE
.LP
Traditionally, the X Window System has provided for both blanking and
non-blanking screen savers. Timeouts associated with these built-in
screen saver mechanisms are limited to idle (dwell) time, and a change
timeout that specifies the change interval for non-blanking screen savers.
.LP
The United States' Environmental Protection Agency (EPA) Energy Star program
requires that monitors power down after some idle time by default.
While it is possible to simply overload the existing screen saver timeouts,
this solution leaves the non-privileged user little to no control over
the DPMS characteristics of his or her system. For example, disabling
DPMS would require some unintended side effect in the core screen saver,
such as disabling the changing of a non-blanking screen saver. Providing
clients with this control requires an extension to the core X Window System
Protocol, and this extension seeks to fill this gap.
.LP
The design goal of the DPMS extension is to be a logical extension to
the traditional screen saver. The protocol and sample implementation is
designed to use the same date types and time units as the screen saver.
The sample implementation works independently from the screen saver so that
policy as it pertains to the interaction between screen saver and DPMS can
be deferred to the user or screen saver application. The extension has
been tested with and shown to work correctly with both the internal blanking
and non-blanking screen savers, as well as with screen saver extension
clients.
.LP
The DPMS extension is designed to be simple, yet export sufficient
VESA DPMS information to enable full function clients to be written.
Included is the ability to sense DPMS capability, set and get DPMS timeouts,
enable and disable individual DPMS modes, enable and disable DPMS (without
destroying timeout values), and sense current DPMS on/off state and
power level.
.LP
There are four power levels specified by the Video Electronics Standards
Association (VESA) Display Power Management Signaling (DPMS) standard.
These are:
.LP
.Ds 0
.TA .2i 1.5i 2.5i 3.5i
.ta .2i 1.5i 2.5i 3.5i
.R
.PN "DPMS Extension Power Levels"
0 DPMSModeOn In use
1 DPMSModeStandby Blanked, low power
2 DPMSModeSuspend Blanked, lower power
3 DPMSModeOff Shut off, awaiting activity
.De
.LP
.LP
It is logical to assume that successive DPMS modes be chronologically
at the same time or later than one another, and the protocol is designed
to enforce this rule.
.LP
Note however that a concious decision is made to decouple the timeouts
associated with screen saver from the DPMS timeouts. While it might be
considered logical to require that the first non-zero DPMS timeout be
greater than or equal to the screen saver timeout, this is intentionally
omitted, leaving this policy decision to the user or the screen saver
application. In the case of a laptop where power may be scarce, the
importance of power savings should supersede the screen saver. If the
laptop user plugs the unit in and power is no longer a scarce commodity,
it may be decided to make DPMS less aggressive, or disable it completely.
.LP
.NH 1
Requests
.LP
.PN "DPMSGetVersion"
.LP
.IP
\fIclient_major_version\fP\^: CARD16
.br
\fIclient_minor_version\fP\^: CARD16
.LP
=>
.IP
\fIserver_major_version\fP\^: CARD16
.br
\fIserver_minor_version\fP\^: CARD16
.LP
If supplied, the \fIclient_major_version\fP and
\fIclient_minor_version\fP indicate what version of the protocol the
client wants the server to implement. The server version numbers
returned indicate the protocol this extension actually supports. This
might not equal the version sent by the client. An implementation can
(but need not) support more than one version simultaneously. The
\fIserver_major_version\fP and the \fIserver_minor_version\fP are a
mechanism to support future revisions of the Display Power Management
Signaling protocol which may be necessary. In general, the major version
would increment for incompatible changes, and the minor version would
increment for small, upward-compatible changes. Servers that support the
protocol defined in this document will return a \fIserver_major_version\fP
of one (1), and a \fIserver_minor_version\fP of one (1).
.LP
.PN "DPMSCapable"
.IP
=>
.IP
\fIcapable\fP\^: BOOL
.LP
This request is used to determine whether or not the currently running
server's devices are capable of DPMS operations. The truth value of this
request is implementation defined, but is generally based on the capabilities
of the graphic card and monitor combination. Also, the return value in the
case of heterogeneous multi-head servers is implementation defined.
.LP
.PN "DPMSGetTimeouts"
.LP
=>
.IP
\fIstandby_timeout\fP\^: CARD16
.br
\fIsuspend_timeout\fP\^: CARD16
.br
\fIoff_timeout\fP\^: CARD16
.LP
This request returns the current values of the DPMS timeout values. All
values are in units of seconds.
.LP
\fIstandby_timeout\fP is the amount of time of inactivity before standby
mode is invoked. The actual effects of this mode are implementation defined,
but in the case of DPMS compliant hardware, it is implemented by shutting off
the horizontal sync signal, and pulsing the vertical sync signal. Standby
mode provides the quickest monitor recovery time. Note also that many
monitors implement this mode identically to suspend mode. A value of
zero indicates that this mode is disabled.
.LP
\fIsuspend_timeout\fP is the amount of time of inactivity before the second
level of power savings is invoked. Suspend mode's physical and electrical
characteristics are implementation defined, but in DPMS compliant hardware,
results in the pulsing of the horizontal sync signal, and shutting off of
the vertical sync signal. Suspend mode recovery is considered to be slower
than standby mode, but faster than off mode, however this is monitor
dependent. As noted above, many monitors implement this mode identically to
standby mode. A value of zero indicates that this mode is disabled.
.LP
\fIoff_timeout\fP is the amount of time of inactivity before the third and
final level of power savings is invoked. Off mode's physical and electrical
characteristics are implementation defined, but in DPMS compliant hardware,
is implemented by shutting off both horizontal and vertical sync signals,
resulting in the power-down of the monitor. Recovery time is implementation
dependant, but frequently is similar to the power-up time of the monitor. A
value of zero indicates that this mode is disabled.
.LP
.PN "DPMSSetTimeouts"
.IP
\fIstandby_timeout\fP\^: CARD16
.br
\fIsuspend_timeout\fP\^: CARD16
.br
\fIoff_timeout\fP\^: CARD16
=>
.IP
.LP
All values are in units of seconds. \fIstandby_timeout\fP is the amount of
time of inactivity before standby mode will be invoked. This is the
lightest level of power savings, and the monitor is generally immediately
ready upon detection of user activity. This is most often implemented by
shutting off the horizontal sync signal to the monitor.
A value of zero disables this mode.
.LP
The \fIsuspend_timeout\fP specifies the amount of time of inactivity
before the screen is placed into suspend mode. Suspend mode is the
middle level of power savings, resulting in a slightly longer recovery
upon detection of activity. Suspend mode is most often implemented by
pulsing the horizontal sync signal, and removing the vertical sync
signal. A value of zero disables this mode.
.LP
The \fIoff_timeout\fP specifies the amount of time of inactivity before
the monitor is shut off. Off mode is the deepest level of power management,
resulting in the greatest power savings and the longest recovery time.
Off mode is most often implemented by removing both the horizontal and
vertical signals. A value of zero disables this mode.
.LP
The values of successive power levels must be greater than or equal
to the value of the previous (non-zero) level. A BadValue error is generated
if an illegal combination is detected.
.LP
.PN "DPMSEnable"
.IP
=>
.IP
.LP
This request enables the DPMS characteristics of the server, using the
server's currently stored timeouts. If DPMS is already enabled, no change is
effected.
.LP
.PN "DPMSDisable"
.IP
=>
.IP
.LP
This request disables the DPMS characteristics of the server. It does
not affect the core or extension screen savers. If DPMS is already
disabled, no change is effected. This request is provided so that DPMS
may be disabled without damaging the server's stored timeout values.
.LP
.PN "DPMSForceLevel"
.IP
\fIpower_level\fP\^: CARD16
=>
.IP
.LP
This request forces a specific DPMS level on the server. If DPMS is
disabled, a BadMatch error is generated. If an erroneous power level
is specified, a BadValue error is returned, and the error value contains
the bad value. If the power level specified is already in effect, no
changes occur. Power Level must be one of DPMSModeOn, DPMSModeStandby,
DPMSModeSuspend or DPMSModeOff.
.LP
.PN "DPMSInfo"
.IP
=>
.IP
\fIpower_level\fP\^: CARD16
.br
\fIstate\fP\^: BOOL
.LP
This request returns information about the current DPMS state of the
display. \fIstate\fP\^ is one of DPMSEnabled or DPMSDisabled.
If \fIstate\fP\^ is DPMSEnabled, \fIpower_level\fP\^ is returned as one
of DPMSModeOn, DPMSModeStandby, DPMSModeSuspend or DPMSModeOff, otherwise
it is undefined.
.LP
.NH 1
Events and Errors
.LP
No new events or errors are defined by this extension.
.NH 1
Encoding
.LP
Please refer to the X11 Protocol Encoding document as this document uses
conventions established there.
.LP
The name of this extension is "DPMS".
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSGetVersion"
1 CARD8 opcode
1 0 DPMS opcode
2 2 request length
2 CARD16 client_major_version
2 CARD16 client_minor_version
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
1 1 Reply
1 unused
2 CARD16 sequence number
4 0 length
2 CARD16 server_major_version
2 CARD16 server_minor_version
20 unused
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSCapable"
1 CARD8 opcode
1 1 DPMS opcode
2 1 request length
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
1 1 Reply
1 unused
2 CARD16 sequence number
4 0 length
1 BOOL capable
23 unused
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSGetTimeouts"
1 CARD8 opcode
1 2 DPMS opcode
2 1 request length
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
1 1 Reply
1 unused
2 CARD16 sequence number
4 0 length
2 CARD16 standby_timeout
2 CARD16 suspend_timeout
2 CARD16 off_timeout
18 unused
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSSetTimeouts"
1 CARD8 opcode
1 3 DPMS opcode
2 3 request length
2 CARD16 standby_timeout
2 CARD16 suspend_timeout
2 CARD16 off_timeout
2 unused
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSEnable"
1 CARD8 opcode
1 4 DPMS opcode
2 1 request length
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSDisable"
1 CARD8 opcode
1 5 DPMS opcode
2 1 request length
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSForceLevel"
1 CARD8 opcode
1 6 DPMS opcode
2 2 request length
2 power_level
0 DPMSModeOn
1 DPMSModeStandby
2 DPMSModeSuspend
3 DPMSModeOff
2 unused
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
.De
.LP
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
.PN "DPMSInfo"
1 CARD8 opcode
1 7 DPMS opcode
2 1 request length
.De
.Ds 0
.TA .2i .5i 1.5i 2.5i
.ta .2i .5i 1.5i 2.5i
.R
=>
1 1 Reply
1 unused
2 CARD16 sequence number
4 0 length
2 power_level
0 DPMSModeOn
1 DPMSModeStandby
2 DPMSModeSuspend
3 DPMSModeOff
1 BOOL state
21 unused
|