IBM 1PA, Operational, Installation, And Maintenance Manual

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For model 8MX
connect a known 2 Mbps mode capable terminal. Check that the LED lights
within 10 seconds.
– If the LED lights, the device was the one preventing the port from running
in 2 Mbps mode mode.
– If the LED does not light, ensure that the host port connected to the Host
Multiplexer is capable of 2 Mbps mode mode.
For models 2EX and 2FX:
Check whether the 2 Mbps LED lights within 10 seconds:
– If the LED lights, that device was the one preventing the port from running
in 2 Mbps mode.
– If the LED does not light, another device might be running in 1 Mbps
mode. Determine whether the first device is running in 1 Mbps mode by
connecting it directly to a WSC port that supports 2 Mbps mode. (The
5250 Express Program displays which mode is being used.)
For models 1PA and 2PA:
After 10 seconds, check whether another workstation on the same WSC port
starts to operate in 2 Mbps mode:
– If the 5250 Express Program mode indicator on the workstation changes to
2x, the device that you disconnected was preventing the port from running
in 2 Mbps mode.
– If the mode indicator does not change, another device might be running in
1 Mbps mode. To determine whether the device that you disconnected
runs in 1 Mbps mode, connect it directly to a WSC port that supports
2 Mbps mode.
Ÿ
If you suspect that at least one device is running at 1 Mbps mode, disconnect
all the devices from the 7299. Then, re-connect them one at a time:
For models 2EX and 2FX:
Check whether the 2 Mbps LED lights within 10 seconds:
– If the LED lights, the device is running in 2 Mbps mode.
– If the LED does not light, the device is not running in 2 Mbps mode.
For models 1PA and 2PA:
After 10 seconds, check the 5250 Express Program mode indicator on the
workstation:
– If the indicator shows 2x, the workstation is running in 2 Mbps mode.
– If the indicator shows 1x, the workstation is running in 1 Mbps mode.
All Devices Are Down
Check whether the baluns and the hub are using the same pairs:
Ÿ
If they are using different pairs, reconfigure the hub. For directions, see
“Changing the Hub Polarity and Pinout Jumpers” on page 3-3.
Ÿ
If they are using the same pairs, check the polarity of the cable:
– If the polarity is reversed, reconfigure the hub. For directions, see
“Changing the Hub Polarity and Pinout Jumpers” on page 3-3.
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Planning, Installation, and Maintenance Guide