Terminal Lockup Troubleshooting Procedures

1. Turn the terminal off and on and do a CTRL ALT F10. If this frees up the terminal, your lockup cause can be traced back to the terminal ROM and some external factor causing them to be altered eg. the terminal went local. Turning the terminal off and then on restores the values saved off in the ROM of the terminal.
2. From another like station, TAKEOVER the console that is locked (as in TAKEVOER Uxx or STn). TAKEOVER will always display the last screen image from the terminal, locked or not. If you TAKEOVER and it hangs right away, then the buffer is full and nothing is going out to the terminal; that's most likely handshaking. If the channel uses hardware protocol and is hung, you will need to use the "B" parameter for TAKEOVER. When you TAKEOVER in bitbucket mode, every character in the channel will get dumped out, which may in itself clear up the lockup.

   If you are active after the takeover is complete, your serial channel is not locked. That tells you to look back at those components connected to the serial channel; i.e., the cable, connector, terminal port, and the terminal itself for the cause of the lockup.

3. PORTS can be used to tell you several things; first, whether keyboard input at the terminal is being received by the COM port or serial port board (hit keys on the terminal and watch the input side of the ports display for that channel). Ports will also tell you what the last character received by the serial port channel was; if you are using XPC protocol, one possible cause for a lockup is the receipt by the terminal of an "OFF" code, which would appear as a 65 or 67 in PORTS. Control P will appear as 9D 99 19 1D, Control S will be 1D B9 39 B9; both of these can cause a terminal to appear to be locked up. In addition, a PRINTSCREEN to a non-existent printer will also cause the terminal to appear to be locked.

   PORTS displays head and tail input and output pointers for the intelligent board. If your channel is hung due to protocol or handshaking, then the head and tail output pointers will not match. If the application has hung the channel, your head and tail input pointers won't match.

4. Use the TERMSET St utility from another station to see the station status.
5. Use the CCIMODE XX utility to determine the current channel status; on intelligent boards, you will not be able to see the communications parameters; on standard boards and COM ports, you will.
6. Use CCIMODE COMX BAUD RESET if you're on a system with an XIOS date of 03/15/92 or later. This will clear all characters from the buffer, reinitialize the serial hardware and reset your baud rate, and very frequently clears a lockup.If you cannot determine and solve the cause of your station lockup with the above steps, printscreen the results of the utilities in steps 3, 4 and 5 and fax them to us.