Technical data

Safety Instructions and Warranty Terms 36
Manual econ sens+ Version 1.40
Modbus Event Value Registers
Pst is the short term flicker value for the last flicker period. Plt is the long term flicker value,
this is the cubic mean value over the last 12 periods.
Name
Register
Short term flicker Pst L1
500
Short term flicker Pst L2
502
Short term flicker Pst L3
504
Long term flicker Plt L1
506
Long term flicker Plt L2
508
Long term flicker PltL3
510
Table - Modbus event value registers
Modbus TCP
When the econ sens+ is used as a Modbus server over TCP/IP, the modbus TCP specification
suggests to use address 255 and port number 502. Other values are possible. This modbus interface
can be used on devices that do not have an RS485 connection.
Modbus RTU
When the econ sens+ is used as a Modbus server over RS485, only the serial line parameters are
required.
Modbus-Gateway
When the econ sens+ is used as a Modbus Gateway, all parameters are required. The modbus TCP
specification suggests to use port number 502. Other values are possible. If the modbus gateway
receives a request over TCP/IP with an address byte that matches its own bus address, it will act as
modbus server. This way, a device can be both gateway and server at the same time. All requests
with a different address byte are sent to the RS485 bus. This modbus interface can be used on
devices that do not have an RS485 connection. Since it cannot pass on request to the RS485 bus, it
will respond with an exception code 0xA “Gateway path unavailable”. The TCP delay is a time in
milliseconds. After the gateway sends a request to the RS485 bus, it will check the RS485 line for a
response. During the TCP delay, it will not check for new requests on the TCP/IP input. After the delay
is over, the gateway is ready to receive new request via the TCP/IP input. It will keep checking the
RS485 line.