My poor mans SMU - The Agilent 66311B

[TheSteve]

The fan is also loud, even when running properly. The fan speed is controlled by the current drain but they don't take into account the voltage out. I am sure not much heat is generated when it's outputting 15 volts @ 3 amps but they really rev that sucker up. Pretty sure mine will get a resistor mod at some point, or possibly even a different fan.

I did add the bottom feet and the front tilting legs as I found a new set I had ordered for a different project, gives it a great look on the bench,

[nctnico]

So far I have modified all my HP power supplies with temperature controlled fans except for a 6572A which has a temperature controlled fan as standard. On the lower power ones (200W) my fan control board starts to turn the fan on when the heatsink gets to 30 deg. C and have the fan run at full speed when the heatsink is at 50 deg. C. In the higher power ones (1kW) the fan control board has the fan running at a low speed when the temperature is below 30 deg. C. On the 200W models the fan only runs slowly when the PSU is loaded to the max. On the 1kW models I don't remember the fans ever going faster than the default speed. All in all I think HP designed the fans so they provide enough cooling with the air vents clogged and the fan blades encrusted in a thick layer of dust!

If the 66311B is making lots of noise I think I'll add my standard fan control board to it.

[Muxr]

Mine arrived a few days ago. No knob, but it had a sticker on it which said "working". I opened it up anyways. Looked good. Fired it up and it appears to be working. Can't really test it until my connector arrives in a few days.

The VFD is good on it, not dim. The fan is loud, will need modding.



In either case, very happy with the score, thanks TheSteve!

[TheSteve]

Tell me how long it takes you to remove the "JRE0016" sticker. Mine came off with enough effort, but it was quicker to trouble-shoot and fix my voltage jumpers then to remove it. Unless of course you don't mind the stickers, then leave it.

I was pondering the difference between the 66311B and the 66321B last night. I can't help but wonder if they are identical hardware with just a firmware change. The service guide for the 66311B doesn't mention the 66321B that I can find. The 66321B has the same spec's but with "battery emulation". I have already used my 66311B in place of battery when testing some lithium chargers and it worked great as a load but the official feature would be nice. You can select the model # in the CAL/config menu but I don't want to risk losing my calibration as it is very good right now.

btw, mine has ROM A.02.04 and the CAL date is 09/08/06

edit - played around a little. First I dumped the config/cal eeprom (93C86) so I had a backup. I then went into the board init menu but my firmware only allows 66311B, 66311D, 66309B and 66309D to be selected. I was able to exit without losing any cal data. So there is no other model I can select that is useful.

Factory fan in mine is a 2410RL-04W-B60
When the 66311B powers on the default "low" speed runs the fan at 8.7 volts. It will ramp up as current goes up. I added a 30 ohm resistor in series with the fan and it still starts just fine and has calmed it down some. The best solution would probably be to buy a quiet fan.
I am currently running the unit limited to 2 amps into my 34461A DCI input to see if I can get any temp rise out of the exhaust air but so far feel very little  increase in temperature. Obviously sinking current will generate some heat but the fan should have no issues dealing with that.

[gslick]

btw, mine has ROM A.02.04 and the CAL date is 09/08/06

edit - played around a little. First I dumped the config/cal eeprom (93C86) so I had a backup. I then went into the board init menu but my firmware only allows 66311B, 66311D, 66309B and 66309D to be selected. I was able to exit without losing any cal data. So there is no other model I can select that is useful.

Do you have the means to read and dump the ROM A.02.04 firmware? I think it's in either a 28- or 32-pin PLCC package.

I think I have either A.02.01 or A.02.02 in my 66309D supplies and there are some additional settings available in the A.02.04 firmware. (For example whether the dual supplies switch on/off together or independently). I don't know for sure the firmware is actually the same between the 66311B, 66311D, 66309B and 66309D models.

How did you dump the config/cal eeprom (93C86)?

[GAD]

Mine arrived a few days ago. No knob, but it had a sticker on it which said "working". I opened it up anyways. Looked good. Fired it up and it appears to be working. Can't really test it until my connector arrives in a few days.

The VFD is good on it, not dim. The fan is loud, will need modding.



In either case, very happy with the score, thanks TheSteve!

Yours looks positively new compared to mine. Anyone else receive one that looks as bad as mine?

[TheSteve]

btw, mine has ROM A.02.04 and the CAL date is 09/08/06

edit - played around a little. First I dumped the config/cal eeprom (93C86) so I had a backup. I then went into the board init menu but my firmware only allows 66311B, 66311D, 66309B and 66309D to be selected. I was able to exit without losing any cal data. So there is no other model I can select that is useful.

Do you have the means to read and dump the ROM A.02.04 firmware? I think it's in either a 28- or 32-pin PLCC package.

I think I have either A.02.01 or A.02.02 in my 66309D supplies and there are some additional settings available in the A.02.04 firmware. (For example whether the dual supplies switch on/off together or independently). I don't know for sure the firmware is actually the same between the 66311B, 66311D, 66309B and 66309D models.

How did you dump the config/cal eeprom (93C86)?

The firmware should be compatible with your model. Have you checked to see what part number the ROM is? If it's compatible with a programmer/socket I have I can dump it. I read the eeprom in circuit with a UPA-USB programmer using an SOIC clip. I don't think I'd program it in circuit though unless the processor was held in reset.

[mtdoc]

Yours looks positively new compared to mine. Anyone else receive one that looks as bad as mine?

Mine is due to arrive on Tuesday. I'll let you know.

[gslick]

The firmware should be compatible with your model. Have you checked to see what part number the ROM is? If it's compatible with a programmer/socket I have I can dump it. I read the eeprom in circuit with a UPA-USB programmer using an SOIC clip. I don't think I'd program it in circuit though unless the processor was held in reset.

The A2 board block diagram in the service manual shows it as a 4Mbit 256Kx16 part and it is an AMD part in a 44-pin PLCC package so that should make it an Am27C4096 on the 5064-0088 version of the A2 board in my 66309D. I haven't gone back to peel off the firmware version part number sticker on the OTP EPROM yet to verify that is the actual part number.

-Glen

[TheSteve]

The firmware should be compatible with your model. Have you checked to see what part number the ROM is? If it's compatible with a programmer/socket I have I can dump it. I read the eeprom in circuit with a UPA-USB programmer using an SOIC clip. I don't think I'd program it in circuit though unless the processor was held in reset.

The A2 board block diagram in the service manual shows it as a 4Mbit 256Kx16 part and it is an AMD part in a 44-pin PLCC package so that should make it an Am27C4096 on the 5064-0088 version of the A2 board in my 66309D. I haven't gone back to peel off the firmware version part number sticker on the OTP EPROM yet to verify that is the actual part number.



-Glen

Well I'm happy to give it a go if you can get me an actual part #.

[gslick]

The firmware should be compatible with your model. Have you checked to see what part number the ROM is? If it's compatible with a programmer/socket I have I can dump it. I read the eeprom in circuit with a UPA-USB programmer using an SOIC clip. I don't think I'd program it in circuit though unless the processor was held in reset.

The A2 board block diagram in the service manual shows it as a 4Mbit 256Kx16 part and it is an AMD part in a 44-pin PLCC package so that should make it an Am27C4096 on the 5064-0088 version of the A2 board in my 66309D. I haven't gone back to peel off the firmware version part number sticker on the OTP EPROM yet to verify that is the actual part number.



-Glen

Well I'm happy to give it a go if you can get me an actual part #.

I double checked and I was not correct the first time. The A.02.02 firmware I have in my 66309D is actually in an AMD Am27C2048-120JC part. That is a 2Mbit (131,072 x 16) OTP EPROM in a 44-pin PLCC package.  Manufacturer Code 01H, Device Code 98H.

Version A.02.02 firmware binary dumped from my 66309D attached in the .ZIP file here.

[TheSteve]

I should be able to dump 02.04 shortly. I have a DIP40 to PLCC44 adapter that I got with my TL866CS programmer however the pin conversion is not quite correct for a 27C2048. The NC pins are connected where Vss needs to be.

[Muxr]

Mine arrived a few days ago. No knob, but it had a sticker on it which said "working". I opened it up anyways. Looked good. Fired it up and it appears to be working. Can't really test it until my connector arrives in a few days.

The VFD is good on it, not dim. The fan is loud, will need modding.



In either case, very happy with the score, thanks TheSteve!

Yours looks positively new compared to mine. Anyone else receive one that looks as bad as mine?

Your image may make it a bit worse than it really is, because you got a lot of lighting in that picture. Mine looks much better than my Keithley 2015 which needs a new VFD, and it doesn't look very warn but my image is also in relative dark (btw I prefer working in the dark with just spotlights, can't stand glare on the screens)

[TheSteve]

This is firmware version A.02.04 as dumped from my 66311B. In the init menu it lets me choose 63311B, 63311D, 66309B or 66309D so those models should be supported by it.

For anyone wanting to dump it with a TL866CS/TL866A programmer two jumpers need to be added to the DIP40 to PLCC44 adapter board to connect the Vss pins. I jumpered PLCC pins 12 to 13 and 33 to 34 on the adapter board. My 66311B uses an Atmel AT27C2048 with chip ID 001E 00F7.

As far condition of my unit the front has some small dents and marks. I removed several stickers from the front as well. The back plastic bezel is cracked but holds together and the chassis itself has had paint scraped off in a few places. I am thinking my VFD is probably 75% as bright as when new.

[gslick]

Cool, thanks for taking the time to dump the A.02.04 firmware.  AMD Am27C2048 parts are no longer available new but Mouser has the Atmel AT27C2048 in stock for around $4 each. I'll have to pick up some blank parts and give the A.02.04 firmware a try.

I do see the COUPLE:OUTPUT string in the A.02.04 firmware binary which isn't present in the A.02.02 firmware binary. That is consistent with the User's Guide part number 5964-8125. Of course that doesn't make any difference in the single output 66311B/D models.

Also I noticed "PEEK" and "POKE" strings in the firmware binary. I wonder if those could be used to read and write the cal/config 93C86 EEPROM? I'll have to try to experiment with that.

[TheSteve]

Cool, thanks for taking the time to dump the A.02.04 firmware.  AMD Am27C2048 parts are no longer available new but Mouser has the Atmel AT27C2048 in stock for around $4 each. I'll have to pick up some blank parts and give the A.02.04 firmware a try.

I do see the COUPLE:OUTPUT string in the A.02.04 firmware binary which isn't present in the A.02.02 firmware binary. That is consistent with the User's Guide part number 5964-8125. Of course that doesn't make any difference in the single output 66311B/D models.

Also I noticed "PEEK" and "POKE" strings in the firmware binary. I wonder if those could be used to read and write the cal/config 93C86 EEPROM? I'll have to try to experiment with that.

I haven't tried it but the 53131A/53132A series of frequency counters lets you read/write the calibration data via GPIB, you could always give that a shot via GPIB or the serial port for fun.

[gslick]

FWIW, it appears that the commands "DIAG:PEEK? #H0000" through "DIAG:PEEK? #HFFFF" will dump the 256KB firmware 4 bytes at a time.

If the config/cal EEPROM is also mapped somewhere in the DIAG:PEEK address space it would take some time to try to figure that out.

[gslick]

As a simple exercise in PyVISA programming I wrote a simple script to read the firmware from a 66309D through the GPIB interface and dump it to a binary file. It took about 22 minutes to run to completion using an E2050A GPIB/LAN gateway to interface to the 66309D. I verified that the firmware binary file dumped using this method exactly matched the A.02.02 binary file produced by dumping the Am27C2048 EPROM using a device programmer.

I'm a complete novice at Python programming and I'm sure there are better and more elegant ways to implement this, but it did the job...

[TheSteve]

Very cool! Perhaps someone will receive a unit with newer firmware and can dump it for the rest of us without even opening it up.

[nctnico]

I have received my 66311B today together with the feet I ordered from Malaysia. Mine has a knob and rear bezel so at least it is complete. After setting it to 230V it worked right away. It seems my one is controlling the fan speed based on the amount of current drawn from it. My 66311B is missing the name plate and the plastic covering the display was dull (which made the VFD hard to read). I polished it back to being shiny using a strong polish for use on a car.

The unit is very heavy indeed. Not so much because of the transformer but due to the steel casing and inner frame. I wish Agilent/Keysight kept using the light weight aluminium chassis and casings.

[TheSteve]

I believe they all control fan speed based on current sourced or sinked - in my case it was loud even at the minimum setting which starts at about 8.7 volts.

[mtdoc]

Mine arrived today and it looks like I lucked out and got one with a knob and a bright display. 

[nctnico]

I checked mine against a Keysight 34461A and it seemed to be 10mV off. One of the reasons is that the setting accuracy isn't that good (a few mV per step). I performed the voltage calibration procedure and that made sure the reading on the 66311B matches the 34461A.

[mtdoc]

Well, I've fired mine up and played around with it a bit. Yes, the fan is loud!.  I think I will replace it with one of these Vantec temp controlled fans.  I did that with my HP 6632A and it worked well. It might be a risk if it was being pushed to its power limits for extended periods but I'm not likely to do that.

Also, I think front binding posts are in order. I see the cutouts are there but no easy access output pads next to them as there is in the HP 6632A.

[Selectech]

My unit arrived today. No knob, but blue tape on the side said it was working -- and it is working. Bright, even display, checked some current & voltage settings. Control buttons all work ok.