RS422 Tests fails

[thermalman]

Hi,
I am trying to test a Tablet PC which can switch the COM port between RS232 and RS422. If I run burn in test and the PC is set to RS232 it passes the test. If I switch to RS422 and run the test I get the following message
" Error while receiving from the COM Port. Check Plug!"

If i then swtich it back to RS232 it works again. I have used a scope to make sure the port is sending and receiving data.
What is Burn in Test looking for
I have also noticed that the TXD and RXD are on pins 2 & 3 on RS232 whereas in RS422 mode they are switched. Could this be causing burn in test to fail?

I am using Burn in Test 5.3

[David (PassMark)]

Yes, this might be the cause. I would think you would need a differently wired loopback plug for RS422. Or a 422 to 232 adpater in between the loopback plug and the port.

[thermalman]

Yes, this might be the cause. I would think you would need a differently wired loopback plug for RS422. Or a 422 to 232 adpater in between the loopback plug and the port.

Hi, Can you tell me what Burn in test looks for when testing a COM port, does it look at the system to make sure that it is sending and receiving data?

[David (PassMark)]

There are a few different test options in the preferences window.

But the test basically tests the existence of the port, if the device drivers are loaded, the ability of the port of send and receive data and the functioning of the control lines.

See the help file for more details.

[h3mp]

apologies for bumping the thread but RS422 doesnt work for me in passmark 7.1

I have Rx+ linked to Tx+ and Rx- to Tx-
In hyperterminal i get the echo straight back when i type.
burnintest complains that no reply was recieved - ive disabled requiring flow control etc but still no luck?

Mark

[h3mp]

apologies for bumping the thread but RS422 doesnt work for me in passmark 7.1

I have Rx+ linked to Tx+ and Rx- to Tx-
In hyperterminal i get the echo straight back when i type.
burnintest complains that no reply was recieved - ive disabled requiring flow control etc but still no luck?

Mark

..It appears it's caused by the RTS line... it needs to be in a certain state for this RS422 port to work.. hyperterminal turns it the required way but burnintest uses the opposite state.. - can this be flipped somehow??

[Ian (PassMark)]

The expected RTS line status can't be flipped in BurnInTest. You could try disabling the RTS/CTS test phase in preferences to change the test to a pure loopback test.