FS8700-71 – TAC I/Net 2000

Driver Version: 1.06

Document Revision: 2

FieldServer Driver – Serial


TAC I/Net 2000


The TAC-I/Net driver allows the FieldServer to transfer data to and from Server and Client devices on a MR LAN over RS-485 using TAC-I/Net driver protocol.

The protocol works over a multidrop RS-485 line and allows only one Client and up to 32 Servers on a network channel.  Servers are assigned station addresses that range from 0 to 31.  The Client does not have a station address.

If more than 320 points are needed on the I/net network an alternative is for the customer to purchase the 7797-15 Modbus RTU interface card.  This interface card will allow 2000 points to be passed to the I/net Sublan.  This will change the application from I/net to Modbus, but it will work.

Fieldserver Mode Nodes Comments
Client 1 Only 1 client node allowed on multidrop systems
Server 32 This is the limit per i/net panel.  The 32 nodes correspond to the maximum of 32 mr’s that an i/net panel supports.


Formal Driver Type


Client or Server


Compatibility Matrix

FieldServer Model Compatible with this driver
FS-x2010 Yes
FS-x2011 Yes
FS-x40 Yes
FS-x30 Yes


Connection Information

Connection type: RS-485 (Two wire, Half-Duplex
Baud Rates: 9600 –Vendor Limitation.  FieldServer supports all standard baud rates.
Data Bits: 8
Stop Bits: 1
Parity: None
Multidrop Capability Yes


Proprietary Physical Interfaces Supported

Fieldserver Model Adapter Model # Vendor Physical Medium


Devices tested

Device Tested (FACTORY, SITE)
TAC I/Net 7793 SITE


Connection configurations

Connection to an I/Net device can be depicted as follows:


Connection Notes

The TAC-I/Net Client driver supplied with the FieldServer is currently only used for emulating TAC-I/Net hardware such as the 7793 MCI and should not be used under normal circumstances.  Please refer to the section on how to configure the FieldServer as a TAC-I/Net Server if you intend to connect the FieldServer to TAC-I/Net hardware as shown in the connection diagram above.  TAC-I/Net hardware such as the 7793 MCI are Client devices to the FieldServer since they initiate polls with commands to the FieldServer which acts as a Server.

It is recommended that the FieldServer have a dedicated i/net port and a dedicated 7793 controller to avoid compatibility problems with other devices on the network.


Communications functions – Supported functions at a glance:

Data Types Supported

FieldServer Data Type Description (or Device Data Type)


Read Operations supported

FieldServer as a Client FieldServer as a Server
Read all points
Quick poll all points


Write (Control) Operations supported

FieldServer as a Client FieldServer as a Server
Control input points
Control output points


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