I have two Nikon D5100's that some time ago I used successfully with a KMTronic usb relay for >30s exposures. I tried to use both the past couple of nights and am having trouble even with 30s exposures.

Problem1 - the relay is not firing for >30s exposures. I have verified the relay is working using the KMTronic relay test program and sending FF 01 01, FF 01 00, and FF 01 03 and both visually checking the LED's and the onscreen responses.

The relay shows up as /dev/ttyUSB0 and that's what's set in shutter release port.
This is astroberry 2.0.4 with Kstars 3.6.0 stable
Is there a particular log file I could provide and, if so, where is it?

Problem2 - even when doing 30s exposures, something is amiss - I either get loads of retries or, if I'm imaging a target, it takes some pics then aborts.

Doing a search, I game across this command: gphoto2 --debug --debug-logfile=gphoto.txt --summary which returns:

Camera summary:
Manufacturer: Nikon Corporation
Model: D5100
Version: V1.01
Serial Number: 90774560000000000000000000000000
Vendor Extension ID: 0xa (1.0)
Vendor Extension Description: microsoft.com: 1.0

Capture Formats: JPEG Undefined Type
Display Formats: JPEG, Undefined Type, Association/Directory, DPOF, Script, Apple Quicktime

Device Capabilities:
File Download, File Deletion, File Upload
Generic Image Capture, No Open Capture, Nikon Capture 1, Nikon Capture 2, Nikon Capture 3

Storage Devices Summary:
store_00010001:
StorageDescription:
VolumeLabel:
Storage Type: Removable RAM (memory card)
Filesystemtype: Digital Camera Layout (DCIM)
Access Capability: Read Only with Object deletion
Maximum Capability: 3987267584 (3802 MB)
Free Space (Bytes): 370720768 (353 MB)
Free Space (Images): 15

Device Property Summary:
Battery Level(0x5001):(read only) (type=0x2) Range [0 - 100, step 1] value: 100% (100)
Image Size(0x5003):(readwrite) (type=0xffff) Enumeration [
'4928x3264',
'3696x2448',
'2464x1632'
] value: '4928x3264'
Compression Setting(0x5004):(readwrite) (type=0x2) Enumeration [0,1,2,4,5,6,7] value: RAW (4)
White Balance(0x5005):(readwrite) (type=0x4) Enumeration [2,4,5,6,7,32784,32785,32787] value: Preset (32787)
F-Number(0x5007):(read only) (type=0x4) Enumeration [0] value: f/0 (0)
Focal Length(0x5008):(read only) (type=0x6) Range [0 - 0, step 1] value: 0 mm (0)
Focus Mode(0x500a):(read only) (type=0x4) Enumeration [1,32784,32785,32786,32787] value: Manual Focus (1)
Exposure Metering Mode(0x500b):(readwrite) (type=0x4) Enumeration [2,3,4] value: Center Weighted Average (2)
Flash Mode(0x500c):(readwrite) (type=0x4) Enumeration [4,32784,32786] value: Auto (32784)
Exposure Time(0x500d):(readwrite) (type=0x6) Enumeration [2,3,4,5,6,8,10,12,15,20,25,31,40,50,62,80,100,125,166,200,250,333,400,500,666,769,1000,1250,1666,2000,2500,3333,4000,5000,6250,7692,10000,13000,16000,20000,25000,30000,40000,50000,60000,80000,100000,130000,150000,200000,250000,300000,4294967295] value: 4.3e+04 sec (4294967295)
Exposure Program Mode(0x500e):(read only) (type=0x4) Enumeration [1,2,3,4,32784,32785,32786,32787,32788,32790,32791,32792,32793] value: M (1)
Exposure Index (film speed ISO)(0x500f):(readwrite) (type=0x4) Enumeration [100,125,160,200,250,320,400,500,640,800,1000,1250,1600,2000,2500,3200,4000,5000,6400,8000,10000,12800,25600] value: ISO 800 (800)
Exposure Bias Compensation(0x5010):(readwrite) (type=0x3) Enumeration [-5000,-4666,-4333,-4000,-3666,-3333,-3000,-2666,-2333,-2000,-1666,-1333,-1000,-666,-333,0,333,666,1000,1333,1666,2000,2333,2666,3000,3333,3666,4000,4333,4666,5000] value: 2.0 stops (2000)
Date & Time(0x5011):(readwrite) (type=0xffff) '20240303T115547'
Still Capture Mode(0x5013):(readwrite) (type=0x4) Enumeration [1,2,32785,32788,32789,32790] value: Single Shot (1)
Burst Number(0x5018):(readwrite) (type=0x4) Range [1 - 100, step 1] value: 1
Focus Metering Mode(0x501c):(readwrite) (type=0x4) Enumeration [2,32784,32785,32786] value: Single Area (32784)
Reset Bank 0(0xd015):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
Auto White Balance Bias(0xd017):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
UseDeviceStageFlag(0xd303):(read only) (type=0x2) 1
Property 0xd406:(readwrite) (type=0xffff) 'Windows/6.0.5330.0 MTPClassDriver/6.0.5330.0'
Property 0xd407:(read only) (type=0x6) 1
Tungsten White Balance Bias(0xd018):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
Fluorescent White Balance Bias(0xd019):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
Daylight White Balance Bias(0xd01a):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
Flash White Balance Bias(0xd01b):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
Cloudy White Balance Bias(0xd01c):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
Shady White Balance Bias(0xd01d):(readwrite) (type=0x2) Range [0 - 168, step 1] value: 84
White Balance Preset Number(0xd01f):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
White Balance Preset Value 0(0xd025):(read only) (type=0x6) 18612648
White Balance Preset Value 1(0xd026):(read only) (type=0x6) 30212431
Color Space(0xd032):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
Video Mode(0xd036):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
Effect Mode(0xd037):(readwrite) (type=0x2) Range [0 - 6, step 1] value: 1
Auto ISO(0xd054):(readwrite) (type=0x2) Range [0 - 1, step 1] value: Off (0)
Exposure Step(0xd056):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 1/3 (0)
Live View AF Area(0xd05d):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 1
Live View AF Focus(0xd061):(readwrite) (type=0x2) Enumeration [0,2,3,4] value: 3
Auto Off Timers(0xd066):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 1
Long Exposure Noise Reduction(0xd06b):(readwrite) (type=0x2) Range [0 - 1, step 1] value: Off (0)
High ISO noise reduction(0xd070):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 2
Bracket Set(0xd078):(readwrite) (type=0x2) Range [0 - 4, step 1] value: AE only (1)
No CF Card Release(0xd08a):(readwrite) (type=0x2) Range [0 - 1, step 1] value: Off (1)
Clean Image Sensor(0xd08f):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 1
Image Comment String(0xd090):(readwrite) (type=0xffff) ' '
Image Comment Enable(0xd091):(readwrite) (type=0x2) Range [0 - 1, step 1] value: Off (0)
Image Rotation(0xd092):(readwrite) (type=0x2) Range [0 - 1, step 1] value: On (0)
Movie Screen Size(0xd0a0):(readwrite) (type=0x2) Range [0 - 9, step 1] value: 9
Movie Microphone(0xd0a2):(readwrite) (type=0x2) Range [0 - 4, step 1] value: 0
MovRecProhibitCondition(0xd0a4):(read only) (type=0x6) 8
Bracketing Enable(0xd0c0):(readwrite) (type=0x2) Range [0 - 1, step 1] value: Off (0)
Exposure Bracketing Step(0xd0c1):(readwrite) (type=0x2) Range [0 - 7, step 1] value: 0
Exposure Bracketing Program(0xd0c2):(read only) (type=0x2) Range [2 - 2, step 1] value: 2
Auto Exposure Bracket Count(0xd0c3):(read only) (type=0x2) Range [1 - 3, step 1] value: 1
White Balance Bracket Step(0xd0c4):(readwrite) (type=0x2) Range [0 - 2, step 1] value: 0
White Balance Bracket Program(0xd0c5):(read only) (type=0x2) Range [2 - 2, step 1] value: 2
ADLBracketingPattern(0xd0c6):(read only) (type=0x2) Range [0 - 0, step 1] value: 0
Lens ID(0xd0e0):(read only) (type=0x2) Unknown (0)
Lens Sort(0xd0e1):(read only) (type=0x2) Range [0 - 1, step 1] value: 0
Lens Type(0xd0e2):(read only) (type=0x2) 0
Min. Focal Length(0xd0e3):(read only) (type=0x6) 0 mm (0)
Max. Focal Length(0xd0e4):(read only) (type=0x6) 0 mm (0)
Max. Aperture at Min. Focal Length(0xd0e5):(read only) (type=0x4) f/0 (0)
Max. Aperture at Max. Focal Length(0xd0e6):(read only) (type=0x4) f/0 (0)
Auto Distortion Control(0xd0f8):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
Scene Mode(0xd0f9):(readwrite) (type=0x2) Range [0 - 18, step 1] value: 18
Nikon Exposure Time(0xd100):(readwrite) (type=0x6) Enumeration [69536,68736,68036,67536,67136,66786,66536,66336,66176,66036,65936,65856,65786,65736,65696,65661,65636,65616,65596,65586,65576,65566,65561,65556,65551,65549,65546,65544,65542,65541,65540,65539,655385,65538,655376,655373,65537,851978,1048586,131073,1638410,196609,262145,327681,393217,524289,655361,851969,983041,1310721,1638401,1966081,4294967295] value: 4294967295
AC Power(0xd101):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
Warning Status(0xd102):(read only) (type=0x2) 0
Maximum Shots(0xd103):(read only) (type=0x2) Range [0 - 99, step 1] value: 9
AF Locked(0xd104):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
AE Locked(0xd105):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
FV Locked(0xd106):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
Active AF Sensor(0xd108):(readwrite) (type=0x2) Range [0 - 11, step 1] value: 11
Flexible Program(0xd109):(readwrite) (type=0x1) Range [-30 - 30, step 2] value: 0
Recording Media(0xd10b):(readwrite) (type=0x2) Range [0 - 2, step 1] value: Card (0)
Camera Orientation(0xd10e):(read only) (type=0x2) Range [0 - 3, step 1] value: 0' (0)
External Flash Attached(0xd120):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
External Flash Status(0xd121):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
External Flash Sort(0xd122):(read only) (type=0x2) Range [0 - 3, step 1] value: 0
External Flash Compensation(0xd124):(read only) (type=0x1) Range [-18 - 18, step 1] value: 0 (0)
External Flash Mode(0xd125):(read only) (type=0x2) Range [0 - 7, step 1] value: 0
Flash Exposure Compensation(0xd126):(readwrite) (type=0x1) Range [-18 - 6, step 2] value: 0.0 stops (0)
HDR Mode(0xd130):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
HDR High Dynamic(0xd131):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 0
HDR Smoothing(0xd132):(readwrite) (type=0x2) Range [0 - 2, step 1] value: 1
Active D-Lighting(0xd14e):(readwrite) (type=0x2) Range [0 - 5, step 1] value: 5
Fluorescent Type(0xd14f):(readwrite) (type=0x2) Range [0 - 6, step 1] value: 3
Autofocus Mode(0xd161):(readwrite) (type=0x2) Range [0 - 4, step 1] value: MF (fixed) (3)
Auto ISO P/A/DVP Setting(0xd164):(readwrite) (type=0x2) Range [0 - 23, step 1] value: 18
ISO Auto(0xd16a):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 1
Remote Timeout(0xd16b):(readwrite) (type=0x2) Range [0 - 3, step 1] value: 1 min (0)
Flash Mode Manual Power(0xd16d):(readwrite) (type=0x2) Range [0 - 5, step 1] value: Full (0)
ISO Auto High Limit(0xd183):(readwrite) (type=0x2) Range [0 - 7, step 1] value: Hi 2 (5)
Live View Status(0xd1a2):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
Live View Image Zoom Ratio(0xd1a3):(readwrite) (type=0x2) Range [0 - 5, step 1] value: 0
Live View Prohibit Condition(0xd1a4):(read only) (type=0x6) 64
Exposure Display Status(0xd1b0):(read only) (type=0x2) Range [0 - 3, step 1] value: No (0)
Exposure Indicate Status(0xd1b1):(read only) (type=0x1) Range [-60 - 60, step 1] value: 0.0 stops (0)
Info Display Error Status(0xd1b2):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
Exposure Indicate Lightup(0xd1b3):(read only) (type=0x2) Range [0 - 1, step 1] value: Yes (1)
ContinousShootingCount(0xd1b4):(read only) (type=0x2) Range [0 - 99, step 1] value: 11
Property 0xd1b5:(read only) (type=0x4) Enumeration [0,32784,32785,32786,32787,32800] value: 0
Flash Open(0xd1c0):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
Flash Charged(0xd1c1):(read only) (type=0x2) Range [0 - 1, step 1] value: No (0)
ApplicationMode(0xd1f0):(readwrite) (type=0x2) Range [0 - 1, step 1] value: 0
ExposureRemaining(0xd1f1):(read only) (type=0x4) Range [0 - 65535, step 1] value: 15
Active Pic Ctrl Item(0xd200):(readwrite) (type=0x4) Enumeration [1,2,3,4,5,6,101,102,103,104,201,202,203,204,205,206,207,208,209] value: 1
Change Pic Ctrl Item(0xd201):(read only) (type=0x4) Enumeration [] value: 0

Okay, I can confirm that something has changed. Whether it's gphoto or something else I don't have the knowledge to determine, but I just issued some relay ops from the command line and have no trouble commanding the shutter on the D5100.

So, what do I do now?