Multi-Tech Systems ISIHP-4SD, ISIHP-4U manual E12 Disables pacing &E13 Enables pacing

Terminal Adapter AT Commands & S-Registers

Selects method by which the TA controls the flow of data to and from the computer, to prevent either device from accepting data faster than it can handle. The TA provides flow control in both directions. When the TA halts data flow, it is called flow control; when the computer halts data flow, it is called pacing.

&E3 Disable flow control by the TA.

&E4 Hardware flow control. &E4 causes the TA to use the CTS signal to regulate flow control. When CTS goes low, data flow from the computer is suspended until CTS goes high again. This method works with pacing, which uses the RTS signal on pin 4. Hardware flow control cannot be enabled unless an error correction protocol is selected.

&E5 XON/XOFF flow control. This is an in-band

method, where the XON and XOFF characters (^Q and ^S, respectively) are inserted into the data stream, rather than using separate control lines. When an XOFF character is detected, the data stream is suspended until an XON character is detected. The drawback to this method is that some files may contain these characters, causing the file transfer to be suspended indefinitely.

&E6 When XON/XOFF pacing is active, the TA responds to and discards the XON/XOFF characters from the computer.

&E7 When XON/XOFF pacing is active, the TA responds to the XON/XOFF characters and passes them through the communications link to the remote device, thereby pacing the remote terminal adapter as well.

&E12 Disables pacing &E13 Enables pacing.

MultiModemISI Hybrid Series, ISIHP-2S/2U/4S/4U/4SD 119