The Common Settings apply to all capture channels. Once these settings have been specified, OK or Apply should be clicked. This tab defines Local Area Network Logon and Drive Mapping, Windows Freeze Recovery, Network Options and displays ComCap license key details.
Local Area Network Logon and Drive Mapping
These options are primarily used when the ComCap Background Service needs to save files on shared network drives. Shared drives mapped for the current user are not available for the service, and login credential may not be available for UNC shares.
Local Drive to Map may be set to UNC Path or a specific drive letter that should have a network share mapped to a Remote PC Name and Share, with a specific User Id and Password. If a specific drive is mapped, it is done as soon as ComCap starts, and unmapped when it closes. It must not duplicate an existing mapped drive letter or share. If UNC Path is specified, then log file name must be full UNC paths without drive letters, ie \\pc\share\file.txt.
The Test Mapping button will test the mapping details, it should connect and then disconnect to the shared drive, with any errors appearing in the Information Log.
Windows Freezing
ComCap provides an automatic workaround for a serious potential problem if Windows temporarily freezes due to the misbehaviour of other applications or hardware. Freezing is normally seen by the mouse being non-responsive and the system tray clock stopping. If a Windows application hogs all the CPU, it may stop Windows and ComCap correctly capturing data.
If ComCap seemingly freezes for more five seconds, a warning message is logged an Alert optionally generated. It is recommended the cause of such freezing is determined and the other application stopped. The Application Priority on the Capture Logging tab may be set to High or Real Time to reduce the likelihood of other applications blocking ComCap. If a freeze exceeds a specified number of seconds, capture may be optionally restarted, but data may still have been lost during the freeze.
Sometimes the freezing can be much longer, in particular if there are disk drive problems or if an EIDE tape drive is being used. A Hewlett-Packard 20 GB Trevan drive used under Windows XP SP1 causes a test PC to freeze for over two minutes while the tape is being positioned at the start and end of backup, and this is devastating for data capture. The long freeze not only causes data to be lost, but confuses various internal timers so no more data is captured.
TCP/IP Send Keep Alive
For TCP Client only, this option enables automatic keep alive messages to be transmitted every few seconds, defaulting to 20 seconds. Keep alive is only needed when there are long gaps during data capture, and a router or firewall may disconnect the TCP/IP connection due to inactivity (perhaps after 5 or 10 minutes). This option should not be needed on LANs. Setting seconds to zero disables Keep Alive, which may upset some routers.
Don’t Check Connections with Ping Echo
As detailed on Network configuration, TCP Client normally sends a ping to a remote server, which is echoed back if the server exists. Some firewalls and routers may be configured to block pings, causing ComCap to fail to receive the echo and be unable to connect. This tick box bypasses the ping, allowing an immediate connection attempt to the remote server. The penalty is Windows takes about 40 seconds to time out a failed connection attempt, compare to 10 seconds for ping.
License Key
Several fields display the ComCap license key details, if found, and may show an expiry date for a limited duration demonstration key.