Cu type – Verilink 9000 Series (34-00271) Product Manual User Manual

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HAPTER

7: B

ISYNC

2780/3780

AND

3270

E. Output Only.

This option, when set to Y, defines this device as output only and

it is not polled in the normal polling sequence. The normal setting is N. See page
170 for further information.

F. Keep Message.

When set to Y, the unit retains a message for the intended device

until it can be delivered. Normally, if the station goes off-line, any existing
messages is flushed. See page 173 for further information.

G. Wait for Host Connection.

When set to Y, the controller stops polling the device

if the host to which it is connected has gone off-line. It is not polled again until the
host is marked on-line. The normal setting is N. See page 173 for further
information.

H. Flush Data if Offline.

Setting this option to Y causes the TXPORT device to

flush any existing data for any 3274 or 3275 device going offline. If this option is
not set, the device may receive one message after a power off/on, even though the
device is not logged on.

CU Type

The CU Type defines the specific Bisync procedure to use for that controller. Valid
entries for this field are as follows.

0 - RMBCS Switch.

This is used for some banking transaction switches. It runs

3270 polled Bisync, but does not use general polling.

1 - IBM 3274.

This complies with IBM 3274 and 3276 Bisync operation using

general poll.

2 - IBM 3275.

This complies with IBM 3275 Bisync operation using general poll.

3 - IBM 2780.

This complies with IBM 2780 and 3780 Bisync operation. This is a

non-polled environment.

4 - IBM 3780.

This is the same as 2780, but ends a transaction with an EOT only if

it does not receive any message from the device for more than the poll timeout.
This speeds up transactions with multiple messages.

5 - 3270 LAN Gateway.

This is used for Bisync LAN gateways that do not support

specific polling used in the 3274/76 Bisync operation. Only general polling is
used.

Selections 3 and 4 are non-polled protocols. The unit port at each end of the link
must a terminal.

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