Hi, Unable to read from a QSFP-DD device.
Have tried 2 devices, on both I get a DEVICE TIMEOUT error.
https://www.fs.com/uk/products/115913.html?now_cid=3946
https://t1nexus.com/product/t1-qsfp-dd-400g-sr8/
Able to read non-DD QSFP devices ok.
Unable to read from a QSFP-DD
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ArT
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Re: Unable to read from a QSFP-DD
QSFP plugged to the same cage is working? (read/write)
If yes, please try to read QSFPDD as SFP (only read) - does it communicate?
If yes - it's using other (older) MSA standard.
If not - try to select 128B page area (not 256B) - does it read?
If it still not read, I suspect USB-C power issue - does power led (red) is light and bright during read, or it's blinking or dark? (adapter should be connected with USB-C to the same motherboard as REVELPROG-IS and USB-C should be capable of power >7.5W)
If yes, please try to read QSFPDD as SFP (only read) - does it communicate?
If yes - it's using other (older) MSA standard.
If not - try to select 128B page area (not 256B) - does it read?
If it still not read, I suspect USB-C power issue - does power led (red) is light and bright during read, or it's blinking or dark? (adapter should be connected with USB-C to the same motherboard as REVELPROG-IS and USB-C should be capable of power >7.5W)
Re: Unable to read from a QSFP-DD
Hi ArT, answers to questions below :
QSFP plugged to same cage works - YES (tried only read)
QSFP-DD device plugged in
Set device to SFP(A0), SFP(A2), SFP, SFP-DD - NO (same error DEVICE TIMEOUT)
select 128B page read - NO
Power LED stays lit brightly, 3.3V measured on QSFP header, VCC3, VCC3P all good, no voltage dip on READ when checked with a scope
QSFP plugged to same cage works - YES (tried only read)
QSFP-DD device plugged in
Set device to SFP(A0), SFP(A2), SFP, SFP-DD - NO (same error DEVICE TIMEOUT)
select 128B page read - NO
Power LED stays lit brightly, 3.3V measured on QSFP header, VCC3, VCC3P all good, no voltage dip on READ when checked with a scope
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- qsfp.jpg (681.91 KiB) Viewed 241 times
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ArT
- Posts: 1609
- Joined: Wed Mar 25, 2015 8:54 am
- Location: Warsaw, Poland
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Re: Unable to read from a QSFP-DD
Communication lines (SDA/SCL) are the same for QSFP and QSFP-DD (the same pins), the only difference is power distribution (additional VCC / GND lines in 2nd row, more power consumption). Each adapter is tested on few transceivers, one of them is FS QSFP-DD-LB, pict below:
If a standard QSFP works in the same cage and you've already verified the power distribution, I'm honestly not sure what is causing the timeout. We would like to test it on our end. Could you please send the unit to us?
Alternatively, I can send you a second adapter to try out. If the issue persists, you could return both your setup and the second adapter to us for further investigation. I'll send you the details via PM.
- fs-qsfpdd.jpg (221.13 KiB) Viewed 214 times
Alternatively, I can send you a second adapter to try out. If the issue persists, you could return both your setup and the second adapter to us for further investigation. I'll send you the details via PM.
Re: Unable to read from a QSFP-DD
Hi Art, Thank you for your reply. I agree the I2C lines are common between the two types and perhaps there is a supply issue. I was able to read both of my QSFP-DD devices in my board using the Aardvark, this confirms both devices are good. I am happy to send the unit back for further investigation, I can also include the 2 QSFP-DD devices to help debug. If you can email the return address I'll post back the items