Understanding Offline State vs Error State

Offline vs Error States

Both Offline and Error states indicate the printer cannot print, but they have different causes:

Offline State : Xi-Text detected printer is offline (variation of Halted state) : Usually hardware/connectivity issue : Often temporary and recoverable

Error State : Unrecoverable error in Xi-Text configuration or operation : Usually software/configuration issue : Requires fixing underlying problem before recovery

What Causes Offline State

Hardware not ready:

• Printer powered off
• Printer in standby/sleep mode
• Printer out of paper
• Printer paper jam
• Printer cover open
• Printer error condition (hardware)

Connectivity issues:

• Cable disconnected
• Serial port signals indicate offline
• Network printer temporarily unreachable
• Terminal server communication lost

Exit code detection:

Setup file configured to treat certain exit codes as offline:

bash

# In setup file:
exit setoffline 1,10-50

When network subprocess exits with these codes, printer enters offline state.

Diagnostic Approach

Step 1: Check Printer Display

View printer in spq:

bash

spq -P  # Show printers view

Look for state and message:

ptr1  <lp0>  a4.ps  offline:Out of paper
ptr2  <srv:9100>  a4.ps  offline

Messages (if shown) indicate detected condition.

Step 2: Check Physical Printer

For local printers:

• Verify power on
• Check paper loaded
• Look for error lights/messages on printer panel
• Clear any paper jams
• Ensure covers closed
• Check cable connections

For network printers:

• Access printer web interface (if available)
• Check printer control panel via terminal server
• Verify printer status via manufacturer tools
• Test network connectivity

Step 3: Test Device Accessibility

For serial/parallel printers:

bash

# Check device responds
sudo -u spooler cat < /dev/lp0
# Press Ctrl+C after moment

# For serial printers
stty -F /dev/ttyS0 -a
# Shows port settings and status signals

For network printers:

bash

# Test connection
telnet printserver 9100

# Or with nc
nc -v printserver 9100

If connection succeeds, printer should be reachable.

Step 4: Review System Log

Check for offline detection messages:

bash

tail -50 /var/spool/spd/spshed_reps | grep "offline"

May show:

Printer ptr1 went offline: No carrier
Printer ptr2 network connection closed unexpectedly

Resolving Offline Conditions

Hardware Issues

Printer powered off:

• Power on printer
• Wait for ready state
• Start printer in Xi-Text:

bash

spstart ptr1

Out of paper:

• Load paper
• Clear any paper-out sensor errors
• Start printer:

bash

spstart ptr1

Paper jam:

• Clear jam following printer manual
• Ensure no torn paper remains
• Close covers fully
• Start printer:

bash

spstart ptr1

Printer error condition:

• Check printer display/lights for specific error
• Resolve indicated problem (toner, drum, maintenance)
• Clear error on printer
• Start printer in Xi-Text

Connectivity Issues

Cable disconnected:

bash

# For serial printers, check cable at both ends
# Verify proper serial cable (not null-modem if direct)

# For parallel printers, ensure cable firmly seated
# Try different cable if available

After reconnecting:

bash

sphalt ptr1
spstart ptr1

Serial port signals:

Some printers use hardware flow control signals (DTR/DSR, RTS/CTS):

bash

# Check serial port status
stty -F /dev/ttyS0 -a

# Look for:
# - DSR (Data Set Ready)
# - CTS (Clear To Send)
# - DCD (Data Carrier Detect)

If signals indicate offline, printer hardware may not be asserting ready signals correctly.

Network printer unreachable:

bash

# Test connectivity
ping printserver

# Check if ping succeeds but port closed
telnet printserver 9100

If network reachable:

• Printer may be rebooting
• Printer in power save mode
• Print server software crashed

Wait a minute and retry:

bash

spstart ptr1

If network unreachable:

• Check network cables
• Verify switch/router operation
• Check printer IP address hasn't changed
• Verify no firewall blocking

Exit Code Configuration

If setup file uses exit setoffline, network subprocess exiting with specified codes triggers offline state.

Check configuration:

bash

# View setup file
cat /usr/spool/printers/ptr1/.device
cat /usr/spool/printers/ptr1/default

# Look for:
exit setoffline 1,10-50

Test network subprocess:

bash

# Extract network command from setup
grep "network=" /usr/spool/printers/ptr1/.device

# Test manually
# Example: network exec '/usr/local/bin/printer-driver args'
/usr/local/bin/printer-driver args
echo $?  # Check exit code

If exit code in setoffline range, offline is expected behaviour.

Offline vs Error Differentiation

How to tell which state:

bash

# View printer status
splist ptr1

# Output shows state:
ptr1 <lp0> a4.ps offline    ← Offline state
ptr1 <lp0> a4.ps error      ← Error state

Or check in spq:

• Switch to printers view (press 'o' from jobs view)
• State column shows current state
• Additional message may appear on right

Key differences:

Recovery Procedure

For offline state:

1. Fix physical issue (power, paper, cables)
2. Verify connectivity (ping for network printers)
3. Start printer:

bash

spstart ptr1

Printer should initialise and enter idle state.

If still offline:

bash

# Halt to clear state
sphalt ptr1

# Wait a moment
sleep 2

# Start again
spstart ptr1

If repeatedly goes offline:

Check for intermittent hardware issues:

bash

# Monitor for repeated offline
watch -n 5 'splist ptr1; tail -5 /var/spool/spd/spshed_reps'

Pattern of repeatedly going offline suggests:

• Intermittent cable connection
• Printer power cycling
• Network instability
• Print server crashes

Error Messages on Offline State

Some printers provide error messages visible in Xi-Text:

bash

splist ptr1
# May show:
ptr1 <lp0> a4.ps offline:Out of paper
ptr1 <srv:9100> a4.ps offline:Paper Jam

These come from:

fberror keyword in setup:

bash

# In setup file:
fberror

Captures last line of stderr from network subprocess and displays it.

To enable error messages:

bash

# Edit setup file
vi /usr/spool/printers/ptr1/.device

# Add:
fberror

Restart printer to activate.

Preventing Offline Conditions

Regular maintenance:

• Keep printers stocked with paper
• Replace consumables before depletion
• Clean printers regularly
• Check cables periodically

Monitoring:

bash

#!/bin/bash
# monitor-printers.sh

while true; do
    for printer in $(splist | awk '{print $1}'); do
        STATE=$(splist -F "%t" $printer)
        
        if [ "$STATE" = "offline" ]; then
            echo "ALERT: $printer offline" | \
                mail -s "Printer Alert" admin@example.com
        fi
    done
    
    sleep 300  # Check every 5 minutes
done

Redundancy:

Configure multiple printers for same form type:

bash

# Add backup printer
spadd -p backup-ptr -d /dev/lp1 -f a4.ps

# Jobs automatically route to available printer