Operating and Maintenance Instructions
210-OMI14229-Iss8.1
CN1116 Full OMI
Page 6 of 47
© ebm-papst UK Ltd 2021
Chelmsford Business Park Chelmsford Essex CM2 5EZ
Telephone: +44(0)1245468555 Fax: +44(0)1245466336
2.0
Introduction
The Modbus Display & Control (MDC) is a device with two RS485 ports, a keypad for setting parameters and a
display to view the status of the connected equipment. The RS485 master port communicates with ebm-papst
Modbus enabled
,
Electronically Commutated (EC) fans with software version 5.0 or later using a two-wire plus
ground RS485 connection. The RS485 slave port communicates with an external Modbus Master device e.g.
Building Management System (BMS) and provide real-time monitoring and control data.
The MDC features a Modbus auto-addressing program to ease installation and commissioning where it
automatically searches and addresses up to 100 EC fans connected to its RS485 master port.
Four different operating modes are supported:
•
Monitor:
o
Monitors pre-defined fan parameters and reports the information via the digital display and the
RS485 slave port (see Tables 1 below).
o
A fault condition is raised by an on-board LED and a volt-free relay.
o
An optional 0-10V differential pressure sensor can provide a signal to the controller to display
either differential pressure or used to calculate and display volume flow.
•
Monitor & Control:
o
As per Monitor operating mode plus the fan speed is controlled by one, or a combination of:
▪
An external 0-10V control signal
connected to the controller’s 0
-10V input.
▪
A third-party Modbus Master device connected to
the controller’s RS485 slave port.
▪
Local control using the controller’s keypad
.
•
Constant Volume / Constant Pressure:
o
As per Monitor operating mode but requires one or multiple 0-10V differential pressure sensors
used by the controller to maintain a constant volume / constant pressure setpoint configured via
the keypad and/or the RS485 slave port.
•
Modbus Relay:
o
This operating mode converts the controller into a simple messenger where it relays all Modbus
information received from the RS485 slave port to the master port, enabling individual fan control
and access to all Modbus Registers of each fan.
The MDC will display the following parameters for each connected fan, and the following system parameters:
Fan Actual Speed (RPM)
Fan Set Point (%)
Fan Serial Number
Fan Motor Temperature (
o
C)
*
1
Fan Electronics Temperature (
o
C)
Fan Hours Run (h)
Fan Power Consumption (W)
Fan Warnings
Fan Alarms
Fan Air Volume (m
3
/h or CFM) or Fan
Air Pressure (Pa or in.w.g)
*
2
System Power Consumption (kW)
Total System Volume (m
3
/h or
CFM) or Total System Pressure
(Pa or in.w.g)
*
2
Table 1 - Information shown on the MDC
Note *
1
- The controller is compatible with all firmware versions of ebm-papst enabled Modbus EC fans version
5.0 and later,
however, on ‘Modbus
LITE’ reduced functionality fans, the parameter ‘Motor Temperature’
is not
available.
Note *
2
-
Volume and pressure measurements require one or more external differential pressure sensors with
a 0-10V output. The supported pressure ranges are 50Pa, 200Pa, 500Pa, 1000Pa, 2000Pa and 3500Pa.
