T8403 Trusted 40 Channel 24 Vdc Digital Input FTA  

The Trusted® Field Termination Assembly (FTA) – 24 Vdc Digital Input T8800 is designed to act as the main interface between a field device generating a digital signal and the Trusted TMR 24 Vdc Digital Input Module T8403.
Features:
• 40 input channels per FTA.
• Industry standard field device connections (2-wire).
• Standard DIN rail compatibility.
• Simple installation and connection.
• 24 Vdc operation.
• SmartSlot connection for ‘one to many’ hot replacement of input modules.
• Fused field power supply per channel.
• On-board Light Emitting Diode (LED) indication of field power supply integrity.

The Trusted 40 Channel 24 Vdc Digital Input Field Termination Assembly T8800 provides termination for a maximum of 40 input channels from various types of field devices which generate a digital input. Figure 2 below shows the configuration of a single channel.

The supply for the field is derived from dual 24 Vdc feeds which are ‘commoned’ via diodes on the FTA. Indication of the presence of the power supply is provided by a green LED. The supply is then fed to each channel.
The supply voltage to the field is fed via the 50 mA fuse. This effectively limits the current in the field loop. The incoming signal (digital) from the field device is fed directly to the digital input module. Line monitoring components (if required) provide the necessary thresholds used by the input module to detect the field loop/device status, i.e. open/short circuit, alarm etc.
The cable linking the 40 channels on the input module to the FTA is terminated at the 96-way socket SK1. SmartSlot (Version 1) signals from the module are connected to SK1. The

SmartSlot connector is SK2 and is also a 96-way socket. This connector is not used where SmartSlot Version 2 is employed within the Trusted System. The dual dc field power supplies are connected to the FTA via a 5-way terminal block PWR TB. The input signals from the field (40-off) are connected by 2-wire arrangements terminated on 12-off 3-way terminal blocks and 2-off 2-way

T8403