Emerson E2, Installation And Operation Manual

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6-14
•
E2 RX/BX/CX I&O Manual 026-1614 Rev 4 5-JAN-2013
6.4.2.2 BACnet IP (Internet Protocol)
The E2 also supports connecting to devices through IP
(Internet Protocol). The device ID is used to identify the
devices.
6.4.2.3 Discovery
BACnet supports discovery of the devices on a net-
work and interrogation of the devices so they report what
data objects they contain and what properties each object
supports.
6.4.2.4 Client-Server
To describe which role the device plays during com-
munication we will use the term: client-server. The client
is the side that actively initiates the request. The server is
the side that passively responds to the client reply. BACnet
devices can act both as client and server.
Most simple MS/TP and IP devices are passive serv-
ers. They wait passively for a system to poll them for data
and only then do the devices respond. The E2 will mostly
be an active client (although it does have to support some
server aspects).
6.4.3 MS/TP Network Connection
to E2
Before setting up a BACnet, the port on the E2 that has
the MODBUS cable connected must be set up as a MOD-
BUS port.
1. Log in to the E2 with Level 4 access.
2. Press

followed by

- General
Controller Info .
3. Press

+

to open the Serial tab of the Gen-
eral Controller Info setup screens.
4. This screen will have a “Connection” field for all
COM ports on the E2. Highlight the COM port
and choose which route it represents such as
“BACnet MSTP-1”.
5. Input the MAC address in the MSTP MAC field
that the E2 will use for the COM port connection.
6. Under the BACnet tab, several parameters can be
changed on the device object.
Figure 6-12
- BACnet Tab
•Object ID - This is the ID used by the E2 when
participating on a BACnet network. The E2 sup-
ports only the Device Object.
• Max Master - This is the highest number of
MS/TP MAC addresses that will be searched for
on an MS/TP network. This number must be
higher than the controller with the highest MS/TP
MAC address. Lowering this number will
improve throughput of data from the E2.
• ADPU timeout - This is the length of time that
the E2 will wait for a response from a controller.
• ADPU retries - This is the number of times the
E2 will attempt to communicate to a controller
before attempting another message.
6.4.3.1 Add and Connect a BACnet
Device
To enable communications between E2 and the BAC-
net, the devices must be added and addressed in E2.
1. Log in to the E2 with Level 4 access.
2. Press

- Connected I/O Boards
and Controllers .
3. On the Third Party tab, enter the number of
BACnet devices in the BACnet number field.
To commission the device:
4. Press

to return to the Network Setup
menu, then select

- Network Summary .