ICS T8448 Trusted TMR 24Vdc Zone Interface Module

The TrustedTM Versatile Field Termination Assembly (VFTA) is designed to
act as the main interface between field devices associated with the detection
and suppression of fire and gas hazards, and the TrustedTM TMR Zone
Interface Module T8448.
Each channel of the VFTA is configurable to enable a variety of field devices
to be connected. These include devices generating both analogue and
digital input signals, and output devices requiring a digital signal at up to 40V
dc.
The 40 channels are arranged in five power groups each comprising eight
identical channels. Each power group is supplied from dual 24V dc feeds
which are ‘commoned’ via diodes on the VFTA. The supply is then fed to
each channel within the group.
The supply voltage to the field is fed via a 315mA fuse. The incoming signal
(0-20mA) from the field device is fed through a 50mA fuse which effectively
limits the input signal. The voltage developed across an input 250R resistor
(high precision 0.1%) is used by the input module to detect the field device
status.
The cable linking the 40 channels on the input module to the VFTA is
terminated at five 10-way connectors. The dual 24V dc power supplies are
connected to the VFTA via five 4-way connectors. Forty 3-way connectors
are used for the field loops.
The VFTA is designed to be mounted on either of the TS32 or TS35 DIN
rails in the horizontal or vertical positions as required