18
7.3.2. Secondary RS-232C Interface
The secondary interface uses only Transmit data and Receive data other than Ground. So,
There is no possibility of hardware Handshake signalused for channel 2) works exactly
the same way as defined for channel 1.
8. Application Examples
8.1. ASCII Terminal to Host for Login
To connect a DTE (Data Terminal Equipment), a standard non-crossed cable can be used
for port 1. Channel one is configured for speed, interface mode (typically 4C, N,8,1) and
flow control (hardware or XON/XOFF). TCP port number is a user-selected arbitrary
number (10000 is fine). Connect Mode 01 (connect with any character--never accept
network initiated connections), remote IP Address set to the host, and the remote port
number to 23 (telnet service). Flush mode can be set to 80 to select the block-saving
packing algorithm, and no buffers are cleared. A disconnect timeout can be set, whereas
the DTR disconnect feature is disabled (00)
8.2. Telnet Server for Device Management
Management of workstations, routers and other equipment through Telnet sessions is
accomplished by defining the EAD 02 as a Telnet server. The EAD 02 accepts
connections over the network and so “connects” directly to the serial port. It is necessary
to either set the port number to 23 (the Telnet” service standard) or to explicitly enable
the Telnet functionality by setting bit6 (hex 40) in the disconnect mode. Recommended
settings:
Connect Mode: C0 (or 40 if inactive DTR signals that the device is not available)
Disconnect Mode: 40 (to enable telnet server)
Flush Mode: 80
Sendchars: 0A 0A (line feed)
The interface mode will usually be 4C (N81, RS.232)
Example: PC or ASCII Terminal to EAD 02
8.3. Printer Connection
The EAD 02 does not support LPD/LPR spooling systems. In order to use the EAD 02 as
a serial print server, your operating system/application must support TCP socket
connections. A serial printer is usually wired like a DTE device. Different printers have
different pin configurations, so be sure to check your printer manual for the correct pin of
EAD 02. The signal goes low if the printer is unable to accept more data (e.g. the printer
buffer is full). It must be connected to the EAD 02’ RTS input. Depending on the model,
the flow control signals are:
