MKIV XP Timer/Chronograph

Please use this article to help understand how to use and troubleshoot your MKIV XP Timer / Chronograph. If you have any questions please let us know. 

1. Timer Mode (TIME)

Turning the Timer ON/OFF

• Power on: With a battery installed, press any button
• Power off: Hold any button for 5 seconds
• Auto-off: The unit turns itself off after approximately 15 minutes of inactivity

Recording Shots

The MKIV XP defaults to "TIMER COMMAND" in delay mode:

1. Press the GO button
2. After 2-3.5 seconds, you'll hear a beep (your start signal)
3. As you fire, the timer automatically displays and records:
   • Shot number
   • Split time
   • Total time for each shot
   • First shot time (remains at the bottom)

Reviewing Shots

Sequential Review

1. Press the REVIEW key
2. The MKIV XP defaults to the most recent string in memory
3. To view a previous string: Enter the string number and press REVIEW
4. To view the current string: Press REVIEW again (without entering a number)
5. The display shows the first shot and "FIND SHOT" on the bottom line
6. Each press of REVIEW steps to the next shot or event in memory

Specific Shot Review

1. Enter the shot number you want to review
2. Press REVIEW

Printing Shot Data

If you have an HP IR printer:

• Press the PRNT key anytime after firing, before or during review

NOTE: External printers are no longer available factory-direct for this model

Starting a New String

• Press the GO button to clear your previous string and begin a new one

Continuing a String

• Press the CST GO button to add time of subsequent strings together (e.g., for IPSC standards drill)
• This will NOT clear the memory like the GO button does

Setting a PAR Time

1. Press the PAR button
2. The timer will prompt: "ENTER PAR TIME AND PRESS SET"
3. Enter the time (e.g., 1.2) and press SET
4. The display shows "PAR TIME 1.20" on the bottom line
5. Press GO to start
6. The timer beeps when the time limit is reached
7. To turn PAR time off: Press PAR, SET without entering a number

NOTE: If you make a mistake when entering a number, use the back arrow key to delete

Setting the Delay

The DLY button controls the type and length of delay between pressing GO and the start signal:

• Default: Random delay of 3 to 3.5 seconds
• To set a custom random delay range:
  1. Press DLY, YES, YES
  2. At "LOWER: 3.00", enter your value (e.g., 5) and press SET
  3. At "UPPER: 3.5", enter your value (e.g., 10) and press SET
  4. Press GO
• To turn delay off: Press DLY, NO, GO (timer will beep immediately when GO is pressed)

Setting Benchmarks

The BNCH button sets beeps at specific times after the start signal (simulates moving/pop-up targets):

1. Press BNCH, YES
2. Enter times (e.g., 2, 3.5, 5, 6.25) pressing SET after each
3. Press GO when finished
4. The timer will beep at these specific times

Cadence Function

Sets periodic beeps at regular intervals:

1. Press CAD, YES
2. Choose whether to start cadence on first shot (YES/NO)
3. Enter initial delay (time from go signal to first cadence beep)
4. Enter cycle delay (time between beeps)
5. Press GO

Keyed Beeps

The KEY button provides a beep a certain number of seconds after a specific shot:

1. Press KEY, YES
2. Enter shot number (e.g., 6) and press SET
3. Enter delay length (e.g., 1.5) and press SET
4. Press SET (without entering a number) to return to "TIMER COMMAND" or press GO to start

Keyboard Lock Out

Prevents accidental timer reset during a shooter's run:

1. Press OPTN until prompted "Lock out go keys?"
2. Press YES
3. The keyboard locks after the next GO command
4. To reset: Press REVIEW, then YES at "ENABLE GO KEY?"

NOTE: The PAR and DLY keys remain active

Lead Calculator

Calculates lead based on bullet and target velocity, and target distance:

1. Press OPTN, OPTN, YES
2. Enter your ammo velocity (e.g., 1050) and press SET
3. Enter target range in yards (e.g., 15) and press SET
4. Enter target velocity in FPS (e.g., 30) and press SET
5. The timer calculates the required lead (e.g., 15.1 inches)

2. Rate of Fire Mode (RPM)

Records Rounds Per Minute (RPM) of your weapon up to 600 RPM:

1. Press the RPM button
2. The display shows "FULL AUTO CMD:"
3. Press GO
4. When "FIRE WHEN READY" appears, fire a fairly long burst
5. Press REVIEW to display:
   • Number of rounds fired
   • Total time
   • Cycle rate

NOTE: The total number of cycles is one less than the number of shots fired

3. Chronograph Mode (CHRN)

Skyscreen System Setup

1. Position the closest Skyscreen sensor 5-10 ft. downrange from shooter
2. Aim so bullets pass over center of each screen at 4-8 inches above sensor
3. Keep cables on the ground as much as possible
4. Keep cables separate from each other
5. Ensure the unit is NOT being hit by muzzle blast
6. Use a new, fully-charged battery
7. Bright overcast days work best
8. On very bright blue sky days, try canting sensors 60-90 degrees left/right
9. For indoor shooting, use an incandescent light over each screen or get the M7 IR Skyscreen Upgrade Kit

Connecting Skyscreens

1. Plug first screen into the START plug on the back of your timer
2. Plug second screen into the STOP plug
3. Switch the timer on
4. From "TIMER COMMAND" press the CHRN button
5. The timer switches to "CHRONO COMMAND" and displays current screen separation
6. Default separation is 18" (M7 Skyscreen System)

NOTE: Older PACT screens have 24" separation. To set different separation: Press SET, enter separation in inches, press SET again

Recording Shots

1. Press GO
2. The display shows "Chronograph mode running"
3. Fire over the Skyscreens
4. Display shows shot number and velocity on top line, average velocity on bottom line (e.g., #001 856.2 FPS and AV 856.2 FPS)
5. For error readings (e.g., "6952.3 FPS"), press the NO key to remove from memory

NOTE: The MKIV XP needs one second between shots to allow smoke to clear