EL.CO. S.R.L. – ECD - INSTRUCTIONS FOR USE - Ver.01 - 12/22 - PAGE
The poll speed during programming and during normal
use must not be less than 50ms.
The maximum length of an RS485 transmission is 400
meters.
3.2.2 – COMMUNICATION PROTOCOL DESCRIPTION
The protocol is a subset of the widely used RTU MODBUS protocol.
This choice ensures ease of connection to many commercial
devices.
The default MODBUS address is 50.
The functions of the RTU MODBUS protocol implemented in ECD
are as follows:
function 3 - reading n words
function 6 - writing a word
Each message contains four fields:
•slave address: values between 1 and 255 are valid;
address 0 (zero) is reserved by RTU MODBUS for
broadcasting messages, but it is not adopted in the ECD
series due to the implicit unreliability of this type of
communication;
•function code: it contains 3 or 6 depending on the specified
function;
•information field: it contains the addresses or the value of
the words, as required by the function used;
•control word: it contains a cyclic redundancy check (CRC)
calculated according to the rules established for CRC16.
The characteristics of asynchronous communication are as follows:
8 bits, no parity, one stop bit.
3.2.3 – DATA EXCHANGE
The exchanged data consists of a 16-bit word. All readable and
writable data appears as 16-bit words allocated in the device's
memory.
The working and configuration parameters of the device can be
read and written via serial communication.
The parameters that can be configured in ECD are listed in
Paragraph 6.
WARNINGS FOR INSTALLATION AND USE
4.1 - PERMITTED USE
The device was designed as a measuring and
adjusting item in compliance with the EN60947-4-2
standard for operation at altitudes up to 2000 m. The
use of the device in applications not expressly
envisaged by the above-mentioned standard must
provide for all the adequate protection measures. The device
CANNOT be used in environments with a dangerous (flammable or
explosive) atmosphere without adequate protection. Remember that
the installer must make sure that the standards relating to
electromagnetic compatibility are complied with even after installing
the device, possibly using special filters. If a breakdown or failure of
the device could create dangerous or harmful situations for people,
things or animals, remember that the system must be set up with
additional electromechanical devices to ensure safety.
4.2 - MECHANICAL ASSEMBLY
ECD must be installed on DIN rail guide. Avoid placing the inside of
the device in places subject to high humidity or dirt that may cause
condensation or introduction into the device of conductive parts or
substances. Make sure that the device has adequate ventilation and
avoid installation in containers where there are tools that can cause
the device to work outside the declared temperature limits. Install
the device as far as possible from sources that can generate
electromagnetic disturbances such as motors, contactors, relays,
solenoid valves, etc.
Keep in mind that once the ECD has been installed on the DIN bar,
its only accessible part will be the front panel.
An installation that does not comply with the provisions listed in this
paragraph could compromise the declared levels of protection.
4.3 - ECD WIRING DIAGRAM
+24VDC
GND
RS485A Modbus, 250 nodes
RS485B
MODBUS A Modbus, 32 nodes
MODBUS B
E passing-through item
4.4 – CONNECTION FROM ONE DEVICE TO ANOTHER
ONE
The devices of the ECD series can connect to other devices via the
e bus connector (code BC-5P) supplied as an accessory.
For connect to the modbus line, there are the appropriate
connection terminals (TC-5PL, TC-5PR).
A battery of devices connected to the bus must
consist of a maximum of 32 devices. TC-5PL and TC-
5PR cannot be mounted on ECD at the same time.
4.5 – SUPPLY METOD
The direct power supply of the modules is foreseen through the
connection of the 24VDC source to each of the terminals
4.5.1 – SMART-SUPPLY FOR OTHER DEVICES
The Smart-Supply system is instead based on the use of the bus
connector. Up to 32 modules, the power distribution via bus takes
place by powering a single module.
In this way, it is sufficient to power ECD to power all the other
compatible devices connected on the bus.
5.1 - DESCRIPTION
ECD has the function of receiving an IP modbus packet via the
Ethernet port, thus replicating it on the RTU 485 modbus ports and,
in case of response, replicating it on the IP modbus.
The product is powered in 24Vdc. The lower part of the device has
1 terminal relating to the RTU modbus serial with the possibility of
having up to 32 nodes.
