
SNM-1000 Node Control Modem Revision 3
Operation MN/SNM1000.IOM
3–50
3.5 User Port Operation
The User Port allows the user at the remote site to communicate with the remote control
SNM-1000 to request the setup and termination of circuits, send and receive service
messages, and configure the SNM-1000. The commands configure and control the
SNM-1000 and the traffic modems that have addresses within the range of 1 through 30.
The remote control SNM-1000 modem always utilizes address zero.
The User Port uses a 9-pin mini-DIN female connector on the rear of the SNM-1000. The
port is configured as a DCE with the pin definitions as shown in the following listing.
Signal Function Name Pin # I/O Signal Level
Receiver Ready RR 1 O EIA-232
Receive Data RD 2 O EIA-232
Send Data SD 3 I EIA-232
Terminal Ready TR 4 I EIA-232
Signal Ground SG 5
Data Mode DM 6 O EIA-232
Request to Send RS 7 I EIA-232
Clear to Send CS 8 O EIA-232
Incoming Call IC 9 O EIA-232
The interface operates at 19.2 kbps, 8 data bits, No Parity, and 1 Stop Bit. Levels are in
accordance with EIA-232. The User Port can also be accessed using an optional Public
Switched Telephone Network (PSTN) dial-up modem.
Comments to this Manuals