DECXRLM—Transmit Rate Limiting
Applications can control the transmit rate limiting feature through the DECXRLM control function.
|Set: limited transmit rate.|
|Reset: unlimited transmit rate.|
Modem Connection and Disconnections
When the terminal makes a connection to the host system through a modem, the terminal performs the following operations to ensure it is ready to send and receive.
- Unlocks the keyboard (if it was locked).
- Clears any transmission in progress.
- Clears the keyboard buffer and all message buffers.
- Clears the input buffer.
- Clears XOFF sent and XOFF received.
Any of the following conditions will disconnect the connection to the host system in VT mode:
- You press Shift F5 ( Shift Break ).
- You use the Recall or Default fields in the Set-Up Directory.
- International model: You change the host port you are using (from the RS-232 port to the EIS-423 port, or from the EIA-423 port to the RS-232 port).
- The terminal loses the data set read (DSR) signal.
- The terminal loses the received line signal detect (RLSD) signal for a period of time you defined in set-up. See the disconnect delay feature in the Communications Set-Up screen.
- The terminal does not receive an RLSD signal within 30 seconds after DSR.
- The terminal receives a self-test command from the host system.
The usual way to disconnect communications is to type Shift F5 ( Shift Break ). The host system's response to the disconnect signal depends on the system and the software.
Terminal-to-Printer Data Flow Control
The terminal sends only data characters to the printer. The terminal does not send XON and XOFF characters. The terminal recognizes only XON and XOFF characters from the printer. Any other characters from the printer are ignored.
When the terminal receives XOFF from the printer, the terminal stops sending data. The terminal starts sending data again when it receives an XON, or when a clear comm operation is performed.
Using C1 Control Characters
Using an 8-bit setting for the printer port implies the use of 8-bit C1 control characters. Using a 7-bit setting implies the use of the 7-bit ESC form of C1 control characters. You select the setting by using the data bits/parity feature in the Printer Set-Up screen.
Note on DECXRLM
Older printers may not recognize the 8-bit form of C1 control characters. With these printers, you must set the printer port to 7-bits for correct operation.