DTR Mode (DT) setting


(see setting description format info here)

Function:Defines the function of the DTR line of the serial port of the DS
Set (S) command format:SDTx, where x: 0 (idle), 1 (connection status)
Get (G) command format:GDT
Init (I) command effect:Initialized unconditionally, through network command, serial command, or quick initialization
Post-initialization value:0 (idle)
Change takes effect:After reboot
Overriding parameter:---
Relevance conditions:---
First introduced:Earlier than "baseline" V3.14/V3.51
See also:Ethernet port and network communicationsSerial port and serial communications


When the DTR Mode is 0 (idle) the DTR line is at HIGH* unless changed by the remote host. Remote host can control the DTR line through Set I/O Pin Status (Sx) instructions or Notification (J) messages .

When the DTR Mode is 1 (connection status) the DTR (output) line of the DS reflects current connection status: the DTR line is LOW* when no data connection is established at the moment and HIGH* when there is a data connection in progress.

Remote host can get current status of the DTR line at any time using the Get I/O Pin Status (Gx) instruction , regardless of whether the DTR Mode is 0 (idle) or 1 (connection status). Status change monitoring for the DTR line can also be enabled and Notification (J) messages generated regardless of the value of the DTR Mode setting.

* HIGH and LOW states are described with respect to the serial ports of DS100R, DS100B, DS203. For EM100, EM120, EM200, EM203(A) the signaling is exactly opposite.