Supervision Network On Rs485 - AERMEC VMF-E19 Manual Del Usuario

LIMITS OF THE TTL NETWORK
All the slave thermostats in the TTL network must have the same type of accessory configured (via Dip 5 and Dip 6) in the Master
unit. For example, it's not possible to configure the Cold Plasma accessory on the master and the electric heater on the slave.
The only diversity permitted is a different purifying device on the master and slave. Refer in particular to the last two types of
accessory in the Dip-Switch SW1 settings table. For instance, the electric heater cannot be configured on the master when the
purifying device is configured on the slave (or vice versa).
Another limit concerns the management of the adjustment dead band: it only needs to be set on the master fan coil as it's
ignored on the slaves because both the setpoint and the operating season depend in any case on the master.
EMERGENCY OPERATION OF THE TTL NETWORK
No ambient probe on the master
If the master thermostat works without an ambient probe (i.e. fault on its own local probe), the operating principle is as
described in the paragraphs "No ambient probe (2 pipes)" and "No ambient probe (4 pipes)".
No ambient probe on the slave
The slave thermostat boards go into emergency mode if their own local probe and that of the master are both faulty. As
explained above, if the slave probe is faulty but the master probe is working correctly, the slaves carry on working with the
probe of the master. If the slaves begin working in emergency mode, they will work at the speed selected on the user interface
and valve Y1 will be opened (this applies for both 2-pipe systems and 4-pipe systems). In addition, slaves working in emergency
mode don't follow the logic of ON-OFF cycles according to the position of the temperature selector - they are always ON (i.e.
ventilation always enabled).
ANTI-FREEZE PROTECTION ON THE TTL NETWORK
Master: as explained in the "Anti-freeze protection" paragraph, the thermostat controls the ambient temperature to ensure
it doesn't fall to freezing levels. If the master is working in this condition, it forces all the slaves to work in AUTO mode with a
setpoint of 12°C, even if they happen to be working normally.
Slave: if, on the other hand, one of the slaves comes within the anti-freeze protection logic (even if the master is working
normally), it will start working in AUTO mode with a setpoint of 12°C. This is the only case in which the slave works with different
settings from those dictated by the master.

SUPERVISION NETWORK ON RS485

The E19 thermostat can also be interfaced with a centralised system via a communication serial based on the RS485 electric
standard and using the standard Modbus RTU protocol. The E19 board is always the slave of the communication.
NETWORK CHARACTERISTICS
• Maximum BUS length = 1000m
• Transmission speed = 19200 baud
• Data bits: 8
• No parity
• Stop bit 2
• Communication protocol = Modbus RTU
OPERATING LOGIC
Once communication with the supervision system has been established, the VMF-E19 thermostat automatically enables the
comfort function - i.e. in relation to the centralised setpoint, the adjustment setpoint of the local interface is ±3 or ±6°C. The E2
thermostat communicates with the centralised system, supplying and receiving information relating to its operating status. The
following list shows the variables that the thermostat can exchange via the communication serial.
NB: the VMF-E19 thermostat can only communicate with the centralised system if it has a user interface or the VMF-IO
expansion is installed.
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AVMFE19LJ 2011 - 5779300_05