Configuration
RS-485 Configuration
4-5
Configuring SNMP
The MSS has a single community (“public”) with read-only access. You can optionally add a single
community with read-write access using the Change Server SNMPSetComm command. See the MSS
Reference Manual for more details.
Once you enable an SNMP write community, you can use SNMP SET operations to configure the following
things on the MSS. Items marked with an asterisk (*) are saved to non-volatile RAM (NVR) and therefore
may take longer to complete.
RS232 MIB:
PortInSpeed* (also changes PortOutSpeed)
PortOutSpeed* (also changes PortInSpeed)
PortInFlowType* (also changes PortOutFlowType)
PortOutFlowType * (also changes PortInFlowType)
AsyncPortBits*
AsyncPortStopBits*
AsyncPortParity *
AsyncPortAutobaud*
Character MIB:
PortName
PortReset
PortInFlowType
PortOutFlowType
PortSessionMaximum
SessionKill
RS-485 Configuration
While the MSS serial ports are initially configured for RS-232 networking, they can also be configured for
RS-485 networking. The RS-485 standard allows a serial connection to be shared like a “party line.” As
many as 32 devices can share the multidrop network. Typically, one device is the master and the other
devices are slaves. There are a few important things to note about RS-485 networking with the MSS.
The MSS can be used in either two-wire or four-wire mode. Refer to the following sections to
determine which mode to use.
The maximum RS-485 network cabling length (without repeaters) is 4,000 feet. Lantronix
recommends the use of shielded twisted-pair cabling.
A large number and varieties of protocols run over RS-485. However, the MSS does not convert or
interpret serial data. It only moves data between serial and Ethernet. Any RS-485 protocol will have
to be implemented by host software.
Note:
See
Appendix C
for the RS-485 pinouts.
To enable RS-485 mode on the MSS, enter the Change RS485 Port [Portlist] Enabled command. This
command can apply to any or all of the serial ports. RS-232 mode is enabled by default.
Figure 4-8:
Enabling RS-485 Mode
Local>> CHANGE RS485 PORT 3 ENABLED