RTD vs. DDE

[pixelart]

Hi,

I have been using Qlink 2.0 for a long time ago and recently tried Qlink 3.0. After took sometime the new stuffs and found my findings as follows:

3.0 vs. 2.0

1. Now the RTD link can include some reference cells from Excel ----> easier and more flexible to the the same result

2. Every time when I open excel file with RTD links. it will automatically update all the links. (no optional for selecting update or not). So you cannot preserve the previous data record.

3. the refresh speed on RTD is slower than DDE link. especially if an excel file has over 200 links together with different cell calculations. DDE performs very much better.


4. there is an old bug on Qlink 2.0 is sometimes it cannot update the links even to restart the Qlink or Excel program....It is very annoying task.

Conclusions.

Both 2.0 and 3.0 have their strength. and since different users out there with different needs and requirements, I hope esignals can keep both RTD and DDE option in Qlink now and forever release.

Thanks

[techuser]

rtd refresh speed

I also notice that the rtd refresh speed is slower than the hotlink dde of Excel. Is there a way to change the rtd refresh speed for esignal? thanks.

[eostrom]

RTD interval

That rate at which RTD links update is determined by design of Microsoft. It does look like it can be adjusted through a registry key for excel 2003 I'm not sure if this works for version beyond that.

Excel does not update RTD data for every single update. It refreshes RTD data periodically based on a system-wide throttle interval named Excel.Application.RTD.ThrottleInterval. You can set the throttle interval with either Visual Basic/VBA or the Registry.

Set the throttle interval:

• Via Visual Basic / VBA: You can set Application.RTD.ThrottleInterval. in immediate mode or in a startup handler.

• Via the Registry: On startup, Excel initializes the throttle interval from the registry value.

For Excel 2002:

HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\
Excel\Options\RTDThrottleInterval
For Excel 2003:

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\
Excel\Options\RTDThrottleInterval
Set the throttle interval to any one of the following values:


-1
Manual mode. Never automatically refreshes.

Excel.Application.RTD.RefreshData must be called.
0 Checks for updates every chance it gets.
>0 Excel waits at least the specified number of milliseconds before getting updates.

[techuser]

Thank you, that's a dword and also does work in Excel 2010. I'll do some testing.

[techuser]

I'm still getting long delays in RTD: five seconds between updates in emini s&p futures and thirty seconds in ten year bond futures, even though the rtd refresh is set at 100 ms.

[techuser]

On a very fast x79 3930K x64 windows 7 pc, with plenty of ram, and rtd refresh set at zero (no throttling of RTD, so maximum possible update speed), here are a few of the problems:

These are the lag times I noted at ~10:30 EST between price updates, in seconds.

ECH: 16 sec (March Euro)
ESH 4 sec (Marsh emini s&p)
U0H 32 sec (March ten yr US bonds)
USH 42 sec (March 30yr US bonds)

At this time of day these figures should all be 2 seconds at most—and ES and U0 should be 1 second.

U0 is the most obviously impossible of these figures. (ES and U0 each trade over 1 million contracts per day, which = about 50 contracts per second.)

Oddly forex currencies update at proper speed (once a second).

This is a serious issue, since realtime prices make a big difference; 30 seconds late is a large gap!

[eostrom]

RTD delay

Checking on these, to see what can be done. I will update here once I have more information.

[techuser]

Eric,

Thank you. Let me add the correct esignal symbols for the commodities:
Ten year March US bonds: QTY H2
30 yr March US bonds: QUS H2
March Euro: 6E H2
March emini S&P: ES H2

This is a critical issue, since the realtime value of the data is lost if updates occur infrequently. Feel free to ask if you need further information about the setup on this end.

Best,
Manuel

[eostrom]

qlink lag

You're not seeing the same lag in eSignal are you?

[techuser]

Re: qlink lag

Originally posted by eostrom
You're not seeing the same lag in eSignal are you?

no, i'm not. I assume you'd update the datetime in rtd even if the price on the next trade is the same.

[eostrom]

QLink delays

Still not exactly sure where this delay is coming from. The QLink program is a very light program when talking about resources and I'm unable to duplicate this delay here. Still looking into this though.

[techuser]

Re: QLink delays

thank you, I haven't seen it since my last post, so perhaps it was some kind of network latency effect, or another variable was at play. If I get a duplication, I'll post again.