Has someone experienced the same? Is there a solution? Seems that Input-Switching via DDM doesn't work consistently.

I've found something in an older thread: https://www.dell.com/community/Monitors/u2415-wont-switch-displays-when-using-DDM/m-p/5098241

❯ .\ddm.exe /SetControl 60 10  // switches to mDP correctly

❯ .\ddm.exe /SetActiveInput mDP // doesn't work on the P4317Q 

❯ .\ddmcmd.exe /GetActiveInput 
GetActiveInput = mDP

GetActiveInput does show mDP als active input after switching with SetControl.

DDM version 1.56.0.2110

"SetControl 60 10" and "SetActiveInput mDP" are the exact same command, with one exception: "SetActiveInput" asks the FW if it supports mDP first, where "SetControl" does not.

Restart DDM, issue a "SetActiveInput mDP" command, and then save the DDM diagnostic report, posting the log here. While holding down the SHIFT key, right click on the DDM system tray icon and select "Save diagnostic report" from the popup menu.

I've issued the following 3 commands after restarting DDM:

Here is the corresponding diagnostic log:

Diagnostic Report, generated 06.01.2023 (10.0.19044)
Copyright (c) 1995-2022, EnTech Taiwan.
Version = 1.56.0.2110
OS = 10.0.19044.2 x64
Mechanism = 3
Account = Standard
Command line = "C:\Program Files (x86)\Dell\Dell Display Manager\ddm.exe" 
////////////////////////////////////////
Configuration settings:
GlassBorder.DELD085.n/a = 0x00000100
AppScan.DELD085.n/a = 0x00000005
FW.DELD085.n/a = 0x00000104
CustomGridxy.DELD085.V7M4J03800NL = 0x0F000848
CustomGrid.DELD085.V7M4J03800NL = 3A060000D7020000C6080000510500000000000000000000000F000048080000A204000004020000140C00006F0400008C030000880000002E0D00008F060000AC0400000E0200001E0C00007904
FW.DELA07B.0FFXD3BS3K5S = 0x00000000
FW.DELA07A.0FFXD3BS3K5S = 0x00000000
FW.DELA07B.0FFXD3BS3JRS = 0x00000000
AutoRestoreWindowLayout = 0x00000000
MRU.DELD085.V7M4J03800NL = 14030D0E052D
GridType = 0x00000000
GridType.DELD085.V7M4J03800NL = 0x00000000
MainUI = 0x06540359
AutoPreset.DELD085.V7M4J03800NL = 0x00000001
LastRC = SetControl 60 10 = Ok
HintShown = 0x00000001
GlassBorder.DELD085.V7M4J03800NL = 0x00000000
AppScan.DELD085.V7M4J03800NL = 0x00000005
DELD085 = 0x00000001
FW.DELD085.V7M4J03800NL = 0x00000104
EApolicy = 2028 2028 2028 2028 2028 2028
LastCheck = 0x0000AF84
LCID = 0x00000407
EnumErrorCount = 0x00000000
////////////////////////////////////////
11:22:37.977...Log opened
11:22:37.983...WinOS = 0
11:22:38.015...LanguageID = 0407 0407 0C07
11:22:38.034...Build = 1.56.0.2110
11:22:38.037...Thunderbolt driver = tbtbusdrv 1.41.1335.0
11:22:38.037...Windows handles = 0001018E 00010120 00010192
11:22:38.041...OS monitor sleep timeout value = 600 ms.
11:22:38.041...Applied DPI = 96-96
11:22:38.042...VM = 0
11:22:38.086...VD = {A2F68DB2-0BCD-4CCF-ADE1-53368FC6B4C7}
11:22:38.092...Registered DDM popup hotkey = Shift+Ctrl+D 6044
11:22:38.095...Registered EA layout MRU hotkey = Shift+Ctrl+Home 6024
11:22:38.097...Registered application window hotkey = Shift+Ctrl+Ins 602D
11:22:38.104...Remote asset management = 1
11:22:38.105...Remote registry service state = 4
11:22:38.250...WMI service state (unless firewalled) = 1
11:22:38.292...DMA = 0x03
11:22:38.305...Starting enumeration
11:22:38.557...Skipping unsupported device MONITOR\LGD05DC\{4d36e96e-e325-11ce-bfc1-08002be10318}\0001
11:22:38.562......Status = 00000000
11:22:38.566...2. DELD085.n/a on Intel(R) Iris(R) Xe Graphics
11:22:38.567......Monitor model = Dell P4317Q
11:22:38.567......Monitor assignment = 1
11:22:38.567......Adapter name = \\.\DISPLAY2
11:22:38.568......Monitor name = DELL P4317Q(miniDisplayPort)
11:22:38.568......Vendor ID = 8086
11:22:38.571......GPU driver = igdumdim64 31.0.101.3790
11:22:38.572......Flags = 00000005.00000003
11:22:38.572......Display tag = 0522A584
11:22:38.572......Monitor handle = 00221345
11:22:38.573......Monitor screen area = 0,0 x 3840,2160 3840x2160
11:22:38.573......Monitor work area = 0,0 x 3840,2120 3840x2120
11:22:38.573......Monitor scaling factor = 100%
11:22:38.574......Raw EDID = 00FFFFFFFFFFFF0010AC85D0000000002B190104A55E35783AFA23A5554E9A270E4849BD4B00D1C081808140950F9500B30081C0010122CC0050F0703E8018103500AD113200001A000000FF000A202020202020202020202020000000FC005034333137510A202020202020000000FD0017501E633C000A2020202020200105
11:22:38.658......VCP10 = 0064004B
11:22:38.662......OS device handle = 00221345.00000000
11:22:38.662......Capabilities string = (prot(monitor)type(lcd)model(p4317q)cmds(01 02 03 07 0c e3 f3)vcp(02 04 05 08 10 12 14(05 08 0b 0c) 16 18 1a 52 60(01 11 12 0f 10) ac ae b2 b6 c6 c8 c9 d6(01 04 05) dc(00 ) df f0(00 08) fd e2(00 0e 12 14 19) e5 f1 f2)mccs_ver(2.1)mswhql(1)) (cached)
11:22:39.013......Firmware string = M2C104
11:22:39.015......Configuration = 230023.FFFF0063.192B
11:22:39.017......Model year = FY17
11:22:39.021......Opcodes supported = 02,04,05,08,10,12,14,16,18,1A,52,60,AC,AE,B2,B6,C6,C8,C9,D6,DC,DF,F0,FD,E2,E5,F1,F2
11:22:39.144......Timing = 133,30 kHz (+), 59,99 Hz (+)
11:22:39.148......Status = 0440001D
11:22:39.149...Ending enumeration
11:22:39.156...New=LGD05DC.0001 DELD085.0005
11:22:39.373...Creating VCP table on DELD085.n/a
11:22:39.446......Opcode 0x12 = 0064004B
11:22:39.586......Opcode 0x60 = 000E0010
11:22:39.710......Opcode 0xE2 = 00FF0000
11:22:39.835...Night light mode = 0
11:22:40.030...Video power down timeout = 600
11:22:40.035...Display powered ON
11:22:40.036...User session connect
11:22:40.054...Auto-saving window layout...
11:22:43.743...Refreshing Dell P4317Q on Intel(R) Iris(R) Xe Graphics
11:22:48.587...SetActiveInput mDP = Ok
11:22:48.590...[RPC] SetActiveInput mDP = Ok
11:23:42.717...Refreshing screen object
11:23:43.459......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:43.521......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:43.649......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:44.667...Old=LGD05DC.0001 DELD085.0005
11:23:44.669...New=DELD085.0005
11:23:44.670...HPD event detected... pausing
11:23:46.251......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:46.380......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:46.495......Error: getting number of physical monitors (0x000005B5) = Ungültiges Handle für den Monitor
11:23:53.176...Changed display configuration
11:23:53.188...Refreshing screen object
11:23:53.521...Starting enumeration
11:23:53.792...Skipping unsupported device MONITOR\LGD05DC\{4d36e96e-e325-11ce-bfc1-08002be10318}\0001
11:23:53.799......Status = 00000000
11:23:53.804...2. DELD085.n/a on Intel(R) Iris(R) Xe Graphics
11:23:53.804......Monitor model = Dell P4317Q
11:23:53.805......Monitor assignment = 1
11:23:53.805......Adapter name = \\.\DISPLAY2
11:23:53.805......Monitor name = DELL P4317Q(miniDisplayPort)
11:23:53.805......Vendor ID = 8086
11:23:53.808......GPU driver = igdumdim64 31.0.101.3790
11:23:53.812......Flags = 00000005.00000003
11:23:53.814......Display tag = 0522A584
11:23:53.815......Monitor handle = 000406C9
11:23:53.816......Monitor screen area = 0,0 x 3840,2160 3840x2160
11:23:53.816......Monitor work area = 0,0 x 3840,2120 3840x2120
11:23:53.817......Monitor scaling factor = 100%
11:23:53.818......Raw EDID = 00FFFFFFFFFFFF0010AC85D0000000002B190104A55E35783AFA23A5554E9A270E4849BD4B00D1C081808140950F9500B30081C0010122CC0050F0703E8018103500AD113200001A000000FF000A202020202020202020202020000000FC005034333137510A202020202020000000FD0017501E633C000A2020202020200105
11:23:53.902......VCP10 = 0064004B
11:23:53.908......OS device handle = 000406C9.00000000
11:23:53.909......Capabilities string = (prot(monitor)type(lcd)model(p4317q)cmds(01 02 03 07 0c e3 f3)vcp(02 04 05 08 10 12 14(05 08 0b 0c) 16 18 1a 52 60(01 11 12 0f 10) ac ae b2 b6 c6 c8 c9 d6(01 04 05) dc(00 ) df f0(00 08) fd e2(00 0e 12 14 19) e5 f1 f2)mccs_ver(2.1)mswhql(1)) (cached)
11:23:54.260......Firmware string = M2C104
11:23:54.264......Configuration = 230023.FFFF0063.192B
11:23:54.265......Model year = FY17
11:23:54.265......Opcodes supported = 02,04,05,08,10,12,14,16,18,1A,52,60,AC,AE,B2,B6,C6,C8,C9,D6,DC,DF,F0,FD,E2,E5,F1,F2
11:23:54.393......Timing = 133,30 kHz (+), 59,99 Hz (+)
11:23:54.397......Status = 0440001D
11:23:54.398...Ending enumeration
11:23:54.404...Old=DELD085.0005
11:23:54.404...New=LGD05DC.0001 DELD085.0005
11:23:54.622...Creating VCP table on DELD085.n/a
11:23:54.695......Opcode 0x12 = 0064004B
11:23:54.833......Opcode 0x60 = 000E0010
11:23:54.957......Opcode 0xE2 = 00FF0000
11:23:55.086...AutoCmdVersions = 0 >> 0
11:24:42.033...Refreshing screen object
11:24:51.835...SetActiveInput DP = Ok
11:24:51.839...[RPC] SetActiveInput DP = Ok
11:24:57.965...SetActiveInput mDP = Ok
11:24:57.968...[RPC] SetActiveInput mDP = Ok
11:25:09.856...SetControl 60 10 = Ok
11:25:09.859...[RPC] SetControl 60 10 = Ok
11:25:21.623...Refreshing Dell P4317Q on Intel(R) Iris(R) Xe Graphics
11:25:33.724...\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
11:25:33.724...Dump: Windows device enumeration
11:25:33.735...Display adapters:
11:25:33.738.....1.Intel(R) Iris(R) Xe Graphics - PCI\VEN_8086&DEV_9A49&SUBSYS_0A421028&REV_01\{4d36e968-e325-11ce-bfc1-08002be10318}\0002
11:25:33.738.....2.Citrix Indirect Display Adapter - PCI\VEN_5853&DEV_1003\{4d36e968-e325-11ce-bfc1-08002be10318}\0001
11:25:33.738...Monitors:
11:25:33.743.....1.DELL P4317Q(miniDisplayPort) - MONITOR\DELD085\{4d36e96e-e325-11ce-bfc1-08002be10318}\0005
11:25:33.743.....2.PnP-Monitor (Standard) - MONITOR\LGD05DC\{4d36e96e-e325-11ce-bfc1-08002be10318}\0001
11:25:33.743...Visible monitors = 2
11:25:33.744...1.DeviceName = \\.\DISPLAY1
11:25:33.744.....DeviceFlags = 00000001
11:25:33.744.....DeviceString = Intel(R) Iris(R) Xe Graphics
11:25:33.744.....DeviceID = PCI\VEN_8086&DEV_9A49&SUBSYS_0A421028&REV_01
11:25:33.744.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{2E5FAC7E-C59A-11EC-A9D4-D8FC4F75DA22}\0000
11:25:33.745.....a.MonitorName = \\.\DISPLAY1\Monitor0
11:25:33.745.......MonitorFlags = 00000003
11:25:33.745.......MonitorString = Generic PnP Monitor
11:25:33.745.......MonitorID = MONITOR\LGD05DC\{4d36e96e-e325-11ce-bfc1-08002be10318}\0001
11:25:33.745.......MonitorKey = \Registry\Machine\System\CurrentControlSet\Control\Class\{4d36e96e-e325-11ce-bfc1-08002be10318}\0001
11:25:33.746.......Raw EDID = 00FFFFFFFFFFFF0030E4DC0500000000001C0104A51D117806B2F5A5534E9B270C5054000000010101010101010101010101010101012E3680A070381F403020350026A51000001A5C2B80A070381F403020350026A51000001A000000FE005630475059803133335746370A00000000000141319E001100000A010A20200023
11:25:33.747...2.DeviceName = \\.\DISPLAY2
11:25:33.748.....DeviceFlags = 00000005
11:25:33.748.....DeviceString = Intel(R) Iris(R) Xe Graphics
11:25:33.748.....DeviceID = PCI\VEN_8086&DEV_9A49&SUBSYS_0A421028&REV_01
11:25:33.748.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{2E5FAC7E-C59A-11EC-A9D4-D8FC4F75DA22}\0001
11:25:33.749.....a.MonitorName = \\.\DISPLAY2\Monitor0
11:25:33.749.......MonitorFlags = 00000003
11:25:33.749.......MonitorString = DELL P4317Q(miniDisplayPort)
11:25:33.750.......MonitorID = MONITOR\DELD085\{4d36e96e-e325-11ce-bfc1-08002be10318}\0005
11:25:33.750.......MonitorKey = \Registry\Machine\System\CurrentControlSet\Control\Class\{4d36e96e-e325-11ce-bfc1-08002be10318}\0005
11:25:33.750.......Raw EDID = 00FFFFFFFFFFFF0010AC85D0000000002B190104A55E35783AFA23A5554E9A270E4849BD4B00D1C081808140950F9500B30081C0010122CC0050F0703E8018103500AD113200001A000000FF000A202020202020202020202020000000FC005034333137510A202020202020000000FD0017501E633C000A2020202020200105
11:25:33.750...3.DeviceName = \\.\DISPLAY3
11:25:33.751.....DeviceFlags = 00000000
11:25:33.751.....DeviceString = Intel(R) Iris(R) Xe Graphics
11:25:33.751.....DeviceID = PCI\VEN_8086&DEV_9A49&SUBSYS_0A421028&REV_01
11:25:33.751.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{2E5FAC7E-C59A-11EC-A9D4-D8FC4F75DA22}\0002
11:25:33.752...4.DeviceName = \\.\DISPLAY4
11:25:33.752.....DeviceFlags = 00000000
11:25:33.752.....DeviceString = Intel(R) Iris(R) Xe Graphics
11:25:33.752.....DeviceID = PCI\VEN_8086&DEV_9A49&SUBSYS_0A421028&REV_01
11:25:33.752.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{2E5FAC7E-C59A-11EC-A9D4-D8FC4F75DA22}\0003
11:25:33.753...5.DeviceName = \\.\DISPLAY5
11:25:33.753.....DeviceFlags = 00000000
11:25:33.753.....DeviceString = Citrix Indirect Display Adapter
11:25:33.753.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.754.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0000
11:25:33.755...6.DeviceName = \\.\DISPLAY6
11:25:33.755.....DeviceFlags = 00000000
11:25:33.755.....DeviceString = Citrix Indirect Display Adapter
11:25:33.755.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.755.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0001
11:25:33.756...7.DeviceName = \\.\DISPLAY7
11:25:33.756.....DeviceFlags = 00000000
11:25:33.756.....DeviceString = Citrix Indirect Display Adapter
11:25:33.756.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.756.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0002
11:25:33.757...8.DeviceName = \\.\DISPLAY8
11:25:33.757.....DeviceFlags = 00000000
11:25:33.757.....DeviceString = Citrix Indirect Display Adapter
11:25:33.758.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.758.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0003
11:25:33.759...9.DeviceName = \\.\DISPLAY9
11:25:33.759.....DeviceFlags = 00000000
11:25:33.759.....DeviceString = Citrix Indirect Display Adapter
11:25:33.759.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.759.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0004
11:25:33.761...10.DeviceName = \\.\DISPLAY10
11:25:33.761.....DeviceFlags = 00000000
11:25:33.761.....DeviceString = Citrix Indirect Display Adapter
11:25:33.761.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.761.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0005
11:25:33.762...11.DeviceName = \\.\DISPLAY11
11:25:33.763.....DeviceFlags = 00000000
11:25:33.763.....DeviceString = Citrix Indirect Display Adapter
11:25:33.763.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.763.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0006
11:25:33.764...12.DeviceName = \\.\DISPLAY12
11:25:33.764.....DeviceFlags = 00000000
11:25:33.764.....DeviceString = Citrix Indirect Display Adapter
11:25:33.764.....DeviceID = PCI\VEN_5853&DEV_1003
11:25:33.764.....DeviceKey = \Registry\Machine\System\CurrentControlSet\Control\Video\{5AB9D46D-D038-11EC-A9DE-C42360FA8961}\0007
11:25:33.766...Total number of monitors enumerated = 2
11:25:33.766...\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
11:25:33.767...Dumping VCP table on DELD085.n/a
11:25:33.833......Opcode 0x02 = 00020002
11:25:33.956......Opcode 0x10 = 0064004B
11:25:34.080......Opcode 0x12 = 0064004B
11:25:34.204......Opcode 0x14 = 000C0005
11:25:34.328......Opcode 0x16 = 00640064
11:25:34.452......Opcode 0x18 = 00640064
11:25:34.575......Opcode 0x1A = 00640064
11:25:34.699......Opcode 0x52 = 00FF0014
11:25:34.839......Opcode 0x60 = 000E0010
11:25:34.962......Opcode 0xAC = 000208B4
11:25:35.085......Opcode 0xAE = 0000176F
11:25:35.207......Opcode 0xB2 = 00080001
11:25:35.331......Opcode 0xB6 = 00050003
11:25:35.453......Opcode 0xC6 = FFFF45CC
11:25:35.576......Opcode 0xC8 = 00005605
11:25:35.700......Opcode 0xC9 = FFFF0104
11:25:35.825......Opcode 0xD6 = 00FF0001
11:25:35.950......Opcode 0xDC = 00FF0000
11:25:36.075......Opcode 0xDF = 00FF0201
11:25:36.198......Opcode 0xE2 = 00FF0000
11:25:36.322......Opcode 0xE5 = 00120000
11:25:36.462......Opcode 0xF0 = 00FF0000
11:25:36.585......Opcode 0xF1 = 00230023
11:25:36.710......Opcode 0xF2 = 00010000
11:25:36.835......Opcode 0xFD = FFFF0063
11:25:36.889......VCP table dumped

I may be misunderstanding, but it seems like what you are trying to do, is begin from a PC running DDM and connected via mDP, then use DDM to switch the active input to DP, and then use DDM to switch the active input back to mDP.  If that's the case, that's just not possible with the P4317. You can only reliably issue commands using DDM over the active input. With newer Dell models you can issue commands over an inactive input but not the P4317.

1. PCa connected via mDP to P43

2. PCb connected via DP to P43

To switch from mDP to DP, you must issue the command from PCa.

To switch from DP to mDP, you must issue the command from PCb

(Again, I may have misunderstood the issue, but I checked a P43 and "SetActiveInput mDP" works correctly.)

@swamped207, thanks - I was hoping that I could issue the command via the inactive input. I had asked our IT department for the newer P4320Qs but got unfortunately got two P4317Qs, which on paper look very similiar.