HP 3000 SERIES II System Service Manual page 118

System Service
4-89. INDICATORS. A number of indicators have been designed into the control PCA to display
the state of various signals. Refer to table 4-6 for a list of identifying signals.
Table 4-6. Selector Channel Control PCA Indicators
SIGNAL INDICATOR DESCRIPTION
CR1 thru CR5 IOCW4 thru 10CWO
Order code from register PCA
CR6 ACTIVE
An order is currently executing
CR7 WCRO
Word count roll over
CR8 DEVEND
Device end from device controller
CR9 XERR
An error occurred
CR10 RR
State of the RR (return residue) FF
CR11 END
State of the END FF
CR12 JUMP
State of the JUMP FF
CR13
CTRL State of the CTRLR FF
CR14 CHAN SR
Service request from device controller
CR15
CHAN SO
Service out from channel
CR16
CHAN ACK
Channel acknowledge from device controller
CR17 FREEZE Clock is frozen by a selected condition
4-90.
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SELECTOR CHANNEL MAINTENANCE PCA (SCMB) 30033-60001
The selector channel maintenance board PCA (SCMB) was designed to aid the maintenance of the
selector channel and multiplexer channel.
4-91. CONFIGURATION. Three jumpers must be configured on the SCMB. See figure 4-20.
They are:
• XWI - This jumper selects whether the SCMB is to be used on the selector channel or the
multiplexer channel. A plug-in containing two jumper wires is installed in XWl. If the jumper
wires are aligned with SC on the PCA, the PCA is enabled for use with the selector channel. If the
jumper wires are aligned with MX, the PCA is enabled for use with the multiplexer channel.
NOTE
When jumper XWI is in the MX position and the SCMB is instal-
led in the multiplexer channel, the selector channel diagnostic
verifies the operation of the SCMB.
• MUX SR - This jU,mper selects a service request number used when the SCMB is used with a
multiplexer channel. This 16-position jumper should be installed to provide a service request
number not used by any· other device controller in the system.
• XW2- These jumpers select SCMB the device number. A jumper wire installed selects a
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in
that position, Use a device number not already assigned.
4-32