Connection Mode (CM) setting

Description

(see setting description format info here)

Function:Defines conditions under which the DS will attempt to establish an outgoing connection to the remote host
Set (S) command format:SCMx, where x: 0 (immediately), 1 (on data or command), 2 (on command), 3 (on command or DSR=HI*)
Get (G) command format:GCM
Init (I) command effect:Initialized unconditionally, through network command, serial command, or quick initialization
Post-initialization value:1 (on data or command)
Change takes effect:After reboot
Overriding parameter:---
Relevance conditions:Current Routing Mode (RM) [setting/ parameter]= 1 (server/client) OR 2 (client)
First introduced:Earlier than "baseline" V3.14/V3.51
See also:Ethernet port and network communications, Serial-to-Ethernet data routing,  UDP data "connections"

Details

Connection Mode defines under which condition the DS attempts to establish an outgoing connection** to current Destination IP-address (DI) [setting / parameter / instruction ] and current Destination Port Number (DP) [setting / parameter / instruction ] :

0 (immediately)The DS attempts to establish an outgoing connection right after the powerup***. The DS will also make this connection "persistent". If the connection is closed (aborted) by the network host the DS will (attempt to) establish it again. Connection timeout (defined by the Connection Timeout (CT) setting) still works in this mode: when the current connection times out the DS aborts it and immediately establishes a new connection. Such behavior "auto-repairs" hanged connections.
1 (on data or command)The DS attempts to establish an outgoing connection when the first serial data is received into the serial port and  committedOR when Establish Connection (CE) instruction is issued.
2 (on command)The DS attempts to establish an outgoing connection only when Establish Connection (CE) instruction is issued.
3 (on command or DSR=HI)The DS attempts to establish an outgoing connection only when Establish Connection (CE) instruction is issued  OR when the DSR line of the serial port is brought HI* (for at least 20ms).

Existing connection can always be terminated by using the Close Connection (CC) instruction or Abort Connection (CA) instruction . With Connection Mode 3 (on command or DSR=HI) it is also possible to close the connection by bringing the DSR line LOW.

Connection Mode is irrelevant when the current Routing Mode (RM) is 0 (server) since in this mode outgoing connections are not allowed at all.

* HI 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.

** Since the DS only allows for a single data connection at a time all conditions described here only apply to a situation when no data connection is established yet.

*** After the IP-address is obtained from the DHCP server if the DHCP (DH) setting is 1 (enabled).