Instruction manual

76
4 8 Data Communication4 8 Data Communication
Two types of interface are available for Data Communication. These are
and interface. Since RS-485 uses a differential architecture to
drive and sense signal instead of a single ended architecture which is used for
RS-232, RS-485 is less sensitive to the noise and suitable for a longer
distance communication. RS-485 can communicate without error over 1 km
distance while RS-232 is not recommended for a distance over 20 meters.
RS-485 RS-232
Tw o types of interface are available for Data Communication. These are
and interface.
Since RS-485 uses a differential architecture to
drive
and sense signal instead of a single ended architecture which is used for
RS-232,
RS-485 is less sensitive to the noise and suitable for a longer
distance
communication. RS-485 can communicate without error over 1 km
distance
while RS-232 is not recommended for a distance over 20 meters.
RS-485 RS-232
Using a PC for data communication is the most economic way. The signal is
transmitted and received through the PC communication Port (generally RS-
232). Since a standard PC can't support RS-485 port, a network adaptor (such
as ) has to be used to convert RS-485 to RS-232 for a PC if
RS-485 is required for the data communication. Many RS-485 units (up to 247
units) can be connected to one RS-232 port; therefore a PC with 4 comm
ports can communicate with 988 units. It can make for a very economic and
powerful package.
SNA10A, SNA10B
Using a PC for data communication is the most economic way. The signal is
transmitted
and received through the PC communication Port (generally RS-
232).
Since a standard PC can't support RS-485 port, a network adaptor (such
as )
has to be used to convert RS-485 to RS-232 for a PC if
RS-485
is required for the data communication. Many RS-485 units (up to 247
units)
can be connected to one RS-232 port; therefore a PC with 4 comm
ports
can communicate with 988 units. It can make for a very economic and
powerful
package.
SNA10A,
SNA10B
RS-485 Benefits:RS-485 Benefits:
Long distanceLong distance
RS-232 Benefits:RS-232 Benefits:
Direct Connection to a PCDirect Connection to a PC
Order ETR-3400-XXXXX2Order ETR-3400-XXXXX2
for RS-232for RS-232
Order ETR-3400-XXXXX1Order ETR-3400-XXXXX1
for RS-485for RS-485
Setup
Enters the setup menu.
Select FULL (Full function) for FUNC.
Select 485 for COMM if RS-485 is required, or 232 if RS-232 is required. Select
RTU (i.e. Modbus protocol RTU mode) for PROT. Set individual address as for
those units which are connected to the same port.
Set the Baud Rate (BAUD), Data Bit (DATA), Parity Bit (PARI) and Stop Bit
Enters the setup menu.
Select
FULL (Full function) for FUNC.
Select
485 for COMM if RS-485 is required, or 232 if RS-232 is required. Select
RTU
(i.e. Modbus protocol RTU mode) for PROT. Set individual address as for
those
units which are connected to the same port.
Set
the Baud Rate (BAUD), Data Bit (DATA), Parity Bit (PARI) and Stop Bit
NOTE: If the ETR-3400 is configured for RS-232 communication, the EI (Event
Input) and input 2 are disconnected internally. The unit can no longer perform
NOTE: If the ETR-3400 is configured for RS-232 communication, the EI (Event
Input)
and input 2 are disconnected internally. The unit can no longer perform
RS-485 SetupRS-485 Setup
RS-232 SetupRS-232 Setup
FUNC=FULL
COMM=485
PROT=RTU
ADDR=Address
BAUD=Baud Rate
DATA=Data Bit Count
PARI=Parity Bit
STOP=Stop Bit Count
FUNC=FULL
COMM=485
PROT=RTU
ADDR=Address
BAUD=Baud
Rate
DATA=Data
Bit Count
PARI=Parity
Bit
STOP=Stop
Bit Count
FUNC=FULL
COMM=232
PROT=RTU
ADDR=Address
BAUD=Baud Rate
DATA=Data Bit Count
PARI=Parity Bit
STOP=Stop Bit Count
FUNC=FULL
COMM=232
PROT=RTU
ADDR=Address
BAUD=Baud
Rate
DATA=Data
Bit Count
PARI=Parity
Bit
STOP=Stop
Bit Count
RS-485 TerminalsRS-485 Terminals
12
13
TX1
TX2
RS-232 TerminalsRS-232 Terminals
12
13
11
TX1
TX2
COM
Multi-units
When you insert an RS-232 module (CM94-2) to the connectors on the CPU
board (C250), you also need to modify the jumper J51 and J52 according
to
If you use a conventional 9-pin RS-232 cable instead of CC94-1, the cable
should be modified for proper operation of RS-232 communication
according to
Section 2-16.
Section 2-16.
When you insert an RS-232 module (CM94-2) to the connectors on the CPU
board (C250), you also need to modify the jumper J51 and J52 according
to
If you use a conventional 9-pin RS-232 cable instead of CC94-1, the cable
should be modified for proper operation of RS-232 communication
according to
Section 2-16.
Section 2-16.