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Thread: Testing Spectra Physics T40-8SS power supply

  1. #11
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    It depends on the exact firmware for the unit you have, but the T40 are actually pretty reasonable units. The one I have you can communicate with over r232, and as you already saw in the manual the command to turn it on is just the ascii 'ON'. The one tricky bit is that you need to have xon/xoff handshaking turned on (but not cts/rts) and the right line termination. It has been a while since I used one without a laser head connected, but I think the commands to set the current are the same as for constant current mode for a millenia. You might try looking for a manual for a BL10, it uses the same series power supply and normaly and does not have a head eeprom so the J40/T40 is used in 'just turn on the diodes' mode.

  2. #12
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    Quote Originally Posted by krazer View Post
    It depends on the exact firmware for the unit you have, but the T40 are actually pretty reasonable units. The one I have you can communicate with over r232, and as you already saw in the manual the command to turn it on is just the ascii 'ON'. The one tricky bit is that you need to have xon/xoff handshaking turned on (but not cts/rts) and the right line termination. It has been a while since I used one without a laser head connected, but I think the commands to set the current are the same as for constant current mode for a millenia. You might try looking for a manual for a BL10, it uses the same series power supply and normaly and does not have a head eeprom so the J40/T40 is used in 'just turn on the diodes' mode.
    I tried sending ON command with carriage return from different terminal programs, at different baud rate with Xon/Xoff flow selected - no luck
    I will try to find B10 manual, thanks.

  3. #13
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    Quote Originally Posted by buffo View Post
    I would expect that the serial link would be used for troubleshooting or monitoring/data logging purposes (thus the command/querry/response format). It seems unlikely that the serial link would also be used to actually start or stop the laser and control the power (diode current).

    Instead, I would expect the start/stop signals and the current control signal to be on the remote connector. The fact that there is an interlock on just the remote connector strongly supports this idea. (You need the remote connected to satisfy the interlocks, but you don't need a serial connection.)

    Sniffing on the serial port certainly won't hurt anything, and you might be able to learn some more about the various operating modes of the unit, but I doubt that you'll be able to control anything.

    Does you manual have any further information about the remote connector? Barring that, does it have any information about the remote unit / box itself? (A schematic would be invaluable...)

    Worst case, if your manual isn't of any help, you may still be OK if Krazer (or another member) has access to a similar remote unit. In that event it's possible you could reverse-engineer one for your unit with their help.

    Adam
    Thanks, so far I am not able to find any details about Remote connector other than requirement to jump pins 8 to 13 to complete boot.

  4. #14
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    I wrote a long description of how to control a T40 with Navigator firmare, but since there's no RF output for a Q-switch, this T40 was probably made for a Millennia. These are normally controlled with a remote, but I'm pretty sure you can do what you want with commands on the serial port. I'm scanning the manual now and will update this post with the procedure to follow.
    Last edited by Junktronix; 05-22-2020 at 08:02.

  5. #15
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    I'm not sure if this T40 has Millennia firmware. When you get the serial connection working, type the command ?WARMUP% and see if it responds with an error or a percentage. If it gives you a percentage, that means it's waiting for the LBO oven in the (missing) head to heat up to around 140C. It should be possible to fake the head temperature with appropriate signals on the Head connector, but I have lots of dead heads here so I just plug one of those in and wait 30 minutes for the oven to (slowly) warm up.

    If it doesn't have Millennia firmware, the command set is very different. Let me know what you find out and I'll point you in the right direction.

  6. #16
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    Quote Originally Posted by Junktronix View Post
    I'm not sure if this T40 has Millennia firmware. When you get the serial connection working, type the command ?WARMUP% and see if it responds with an error or a percentage. If it gives you a percentage, that means it's waiting for the LBO oven in the (missing) head to heat up to around 140C. It should be possible to fake the head temperature with appropriate signals on the Head connector, but I have lots of dead heads here so I just plug one of those in and wait 30 minutes for the oven to (slowly) warm up.

    If it doesn't have Millennia firmware, the command set is very different. Let me know what you find out and I'll point you in the right direction.
    Hello, I am trying to establish serial communication with no success. Serial port is 8-N-1 Xon/Xoff, varied baud rate from 1200 to 9600, checked serial cable, it is straight through (2-2, 3-3, 5-5). Tried commands ?V and ?WARMUP% with CR at the end. Tried two different terminal programs Termite and Hyper terminal - having no response from the unit.

    Wondering if cross-over serial cable would be more appropriate (2-3, 3-2, 5-5).

    Thank you for your help.

  7. #17
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    The baud rate is definitely 9600. I always connect to the Navigator firmware with no handshake. Try turning off XON/XOFF and if you still don't get a response, try swapping pins 2 and 3. I have always had good luck with PuTTY. It's free.

    Another super basic test is to loop pins 2 to 3 and make sure you see each character you type.

    Quote Originally Posted by AP2020 View Post
    Hello, I am trying to establish serial communication with no success. Serial port is 8-N-1 Xon/Xoff, varied baud rate from 1200 to 9600, checked serial cable, it is straight through (2-2, 3-3, 5-5). Tried commands ?V and ?WARMUP% with CR at the end. Tried two different terminal programs Termite and Hyper terminal - having no response from the unit.

    Wondering if cross-over serial cable would be more appropriate (2-3, 3-2, 5-5).

    Thank you for your help.

  8. #18
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    And just to be clear, <cr> means 'carriage return', in other words, press the enter key.

    Quote Originally Posted by Junktronix View Post
    The baud rate is definitely 9600. I always connect to the Navigator firmware with no handshake. Try turning off XON/XOFF and if you still don't get a response, try swapping pins 2 and 3. I have always had good luck with PuTTY. It's free.

    Another super basic test is to loop pins 2 to 3 and make sure you see each character you type.

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