PATTON ELECTRONICS CO. | 3040/V35 | INSTALLATION AND OPERATIONS MANUAL |
139001UA
Anti-streaming
A typical problem often encountered is a “STREAMING” remote terminal. The streaming problem can tie up an entire circuit until the offending device has recovered or is powered down. A streaming condition occurs when a Sub-Channel remains active, disrupting the polling sequence. The 3040/V35 (CTS MD-V.35/TCB) provides two user selectable modes of controlling a streaming condition, an automatic anti-streaming Abort Timer with eight selectable block lengths and a setting to disable anti-streaming for large data block transfers, and a manual Operator Control mode (front panel push button switch).
Automatic Anti-streaming- Automatic Anti-Streaming will block the asserted control signal from the Sub-Channel Port, releasing the 3040/V35 (CTS MD-V.35/TCB) to accept requests from any other Sub-Channel that has not been locked out due to a streaming condition. When a Sub-Channel is locked out for streaming, a visual indication, by Sub-Channel, is provided on the front panel. The Sub-Channel will no longer receive data or CTS from the Master Port.
Any data sent to the Master Port by the streaming device will be lost. Once a Sub-Channel is locked out due to streaming, the Sub-Channel will remain locked out until the attached device removes the streaming condition. If RTS is held active, RTS must become inactive, if continuous data transitions have triggered the Anti-Stream logic, the transitions must stop before the 3040/V35 (CTS MD-V.35/TCB) will clear the Anti-Stream logic to that Sub-Channel. Removing the Sub-Channel via the front panel disable switch will not clear the Anti-stream logic for a Sub-Channel once it has been activated.
Manual Anti-Streaming- If manual Anti-Stream protection is chosen, a streaming condition caused by one of the attached terminals can be quickly corrected by the 3040/V35 (CTS MD- V.35/TCB) via the associated front panel locking switches. A switch is provided for each Sub- Channel and permits the rapid removal of a streaming terminal without having to disconnect any cables or power down the offending terminal. Terminals may be selectively removed for self-test and maintenance without affecting the remaining Sub-Channels. Once the streaming condition has been corrected, the front panel switch is simply depressed to the locked (Enable) position (Green indicator ON) to re-establish normal operation. Removing a Sub- Channel with the front panel switch will block data from the Sub-Channel going to the Master Port but will not block data going from the Master Port to the Sub-Channel as the Automatic Anti-Stream option did.
Channel Selection Modes
The 3040/V35 (CTS MD-V.35/TCB) provides two selectable Sub-Channel service modes of operation, the Scanning Mode and Priority Mode. Depending on system requirements, either mode may be selected by internal DIP switch settings. Both modes switch on activity from the Sub-Channel.