We have a problem with speed in transfering data via
TCP/IP protocol from RT system (Pharlap) to Windows PC. For strings of length of 50 kByte it takes around 20 seconds to come to
PC, which is unacceptable for purposes of our real-time system. When runing the
same program and sending strings of the same lenght from Windows LabView on
PC to another PC, things works fine. It seems that this issue with TCP
data transfer speed comes around only when we try to use intentional TCP
data sending in our program on Real Time target. Labview on RT
target works OK, and refresh rates of online data from real-time target on front
panel are normal. Browsing NI discussion forums we learned that there is known
problem with RT 8186 controlers. RT 818x controllers working in Full-Duplex TCP
mode causes serious slowdown and data loss in TCP and FTP communicaton. As a
solution it is recomended to try working with Half-Duplex mode TCP.
The Problem:
So in order to change duplex mode of ethernet card on my
controller I go to MAX->Remote Systems and choose my
system. Then I go to Advanced Ethernet Settings of that system and from
drop-down menu of Media Mode choose 100Megabit/ Half-Duplex Mode (I have 4 modes
offered: 100 Megabit/Full Duplex, 100 Megabit/Half
Duplex, 10 Megabit/Full Duplex, 10 Megabit/Half Duplex ). MAX then asks me to
reboot my RT system and I say OK. After the system reboots, when I look under
advanced TCP settings I can see that the mode is still 100 Mbit/ Full Duplex and
that it hasn´t changed. If I try to change mode to anything else offered than
100 Mbit/Full Duplex, there is no change after reboot.
So, the question is: How to force duplex mode of
controller to change? Is there anything I can write to one of .ini files to
change it, or do I need some other version of software
(drivers) maybe?
We are using configuration:
RT Controller NI PXI 8186
MAX 4.0.0.3010
LabView 7.1 Real-Time (on RT Controller)
NI Daq-mx 8.0.0
Intel 8254x Ethernet Driver 1.1.0.3.0 (on RT)
Labview 7.1 (on Windows PC)
RT system and PC´s are on 100 Mbit LAN
Thank you!
