Ritron DATAFLOW RTU Technical Manual page 52

8.7 EXAMPLE 6 demonstrates theDATAFLOW RTU as a MODBUS device using direct
data access. The configuration consists of a remote RTU with another RTU connected to a
MODBUS controller, utilizing RTU Programming Software as the MODBUS controller.
Each RTU has five digital inputs and one analog input.
NOTE: In real applications the MODBUS controller is a PLC or a SCADA program
operating with a MODBUS driver.
8.7.1 RTU ID 1 SETUP: Example 6 requires oneDATAFLOW RTUto be wired and its
hardware configured according to Figure B12 -EXAMPLE 6 ID 1 Wiring Diagram on
page B-36. Load Software Programming configuration file
1.
When configuration of RTU ID 1 is completed, turn the RTU power OFF then back ON to
ensure the RTU microprocessor addressing data is updated. Refer to the NOTE with 8.7.4
for further details.
8.7.2 RTU ID 2 SETUP: Example 6 requires the other DATAFLOW RTU to be wired and its
hardware configured according to Figure B 13 - EXAMPLE 6 ID 2 Wiring Diagram on
page B-37. Load Software Programming confi
2.
8.7.3 EXPLANATION: Although the RTU can operate in two different MODBUS modes,
Example 6 demonstrates direct access only. In this mode, the remote RTU is polled by RF
whenever data is required, generating a large amount of RF traffic.
NOTE: This configuration is recommended only for applications having long polling
intervals (over 2 minutes) and few RTU's (fewer than 5).
8.7.4 Examine the configuration ofRTU ID 1 and RTU ID 2. Because the RTU's are no longer
in control of the process and are simply MODBUS devices under control of the MOD BUS
controller:
•
XMIT CHECK IN is set to 0.
•
SEND LIST is all O's.
•
REPEAT LIST is all O's.
•
All inputs have INITIATE XMIT set to NO.
•
All outputs have USED set to NO.
Examine the SCADA CONFIG. screen display for RTU ID 1, containing four
NOTE:
SCADA points stored in EEPROM. The four points load into FULL SCADA
list at power ON. Cycling the power updates data for this screen. In Example
6, the END RTU ID and the TO ID are the same ID because an RTU is the
MODBUS device being controlled.
Software/ Programm
( B-22)
www.TwoWayRadioEquipment.com | (800) 878-7829 | Sales@TwoWayRadioEquipment.com
tion file
gura
EXAMPLE6
EXP6ID1 .USR
EXP6ID2.USR
(Example 6 continued on next page)
into RTU ID
into RTU ID