Daikin EWWP014KBW1N, Руководство по эксплуатации, Страница: 13 / 20

EWWP014~065KBW1N
Packaged water-cooled water chillers
4PW61660-1A – 04.2012
Operation manual
12
Locking the controller keyboard
Once user parameter
h09
is set to
0
, the following advanced
features can no longer be carried out by means of the controller:
■
modifying direct and user parameters (parameters can be
displayed but not modified),
■
resetting the timers.
■
switching the unit on/off in cooling or heating
When user parameter h09 is set to 1 , the above-described
advanced features can be carried out using the controller.
To modify user parameter h09 value from 1 to 0 , the standard user
parameter modification procedure can be used with the standard
password "
22
". Refer to "How to consult and modify the user
parameters" on page 10 .
To modify user parameter h09 value from 0 to 1 , the user
parameter modification procedure can be used with dedicated
password "
11 ". Refer to "How to consult and modify the user
parameters" on page 10 .
BMS
CONNECTION MODBUS
By installing the optional kit address card EKAC10C, you will be able
to communicate with your chiller through a Building Management
System or supervisory system via the Modbus protocol.
General description of Modbus
The address card communicates using the Modbus protocol.
Different parts of the communication network
■
The communication network consists of two major players:
■
The Building Management System (BMS) or supervisory
system.
■
The chiller or multiple chillers.
■
The BMS or other supervisory system is able to communicate
with the chillers through the address card.
The management of the communication occurs in accordance
with a master-slave structure in polling, where the supervising
BMS is the master and the address cards are the slaves.
■
The chiller unit can be identified by the supervisor through the
assignment of an address within the Modbus network. The
address of the chiller unit can be programmed during the
configuration of the BMS settings.
■
The variables database of every chiller with installed address
card is the point of reference for the supplier of the supervisory
system in Modbus to assign a suitable meaning to the variables.
The variables can be read and/or written by the supervisory
system. Whether the variables are read-only or read/write
depends on the connected chiller and/or the application program
being used.
-
If the supervisory system assigns a value to a variable with
read-only status, the command will not be executed at all.
- Variables requested by the supervisory system that are not
available in a chiller with an address card are sent from the
address card to the supervisory system with zero value. The
supervisory system will have to manage these properly.
- In case the supervisory system tries to write a value of a
parameter that is out of range, the writing will be ignored.
General information about the Modbus protocol
The Modicon Modbus protocol implemented in the address card
complies with the content of the following document:
Modicon Modbus Protocol
Reference Guide
June 1996, PI-MBUS-300 Rev. J
The Modbus protocol implemented is of the RTU (Remote Terminal
Unit) type based on character tranmission times. The configuration
uses the multi-drop feature of RS485. The address sent within the
Modbus packet addresses the chiller unit.
Implemented RS485 communication settings for the Modbus
protocol
The RS485 communication settings are implemented as follows:
■
Baud-rate: 9600
■
Stop bit: 2
■
Parity: none
Implemented commands for the Modbus protocol
The implemented commands in the program are as listed:
Note that:
■
Due to the variety of chillers with installed address cards, no
distinction is made between input variables (with read-only
status) and output variables (with read/write status) so that the
knowledge of the database and its management depends on the
part present on the supervisory system.
■
Due to the general nature of the system, the address card
answers in the same way to various Modbus commands.
Modbus command Meaning Notes
01 read coil status Read digital
variable(s) obtains current status (ON/
OFF) of a group of logic coils
or discrete input
02 read input
status Read digital
variable(s) obtains current status (ON/
OFF) of a group of logic coils
or discrete input
03 read holding
registers Read analogue
variable(s) obtains current binary value
in one or more holding
registers
04 read input
registers Read analogue
variable(s) obtains current binary value
in one or more holding
registers
05 force single coil Write individual
digital variable(s) forces single coil to ON or
OFF status
06 preset single
register Write individual
analogue variable(s) places a specific binary
value into a holding register
15 force multiple
coils Write series of
digital variables forces a series of
consecutive logic coils to be
defined to ON or OFF status
16 preset multiple
registers Write series of
analogue variables places specific binary values
into a series of consecutive
holding registers