User Guide
FS -8700-02 Modbus Plus     Driver Manual 
FieldServer Technologies 1991 Tarob Court, Milpitas, California 95035 (408) 262-2299 fax: (408) 262-9042 
Visit our website: www.fieldserver.com E-mail: support@fieldserver.com 
Page  2
Address 
Switches 6--1   Address 
Switches 6--1   Address 
Switches 6--1 
14  0 0 1 1 0 1  36  1 0 0 0 1 1   58  1 1 1 0 0 1 
15  0 0 1 1 1 0  37  1 0 0 1 0 0  59  1 1 1 0 1 0 
16  0 0 1 1 1 1  38  1 0 0 1 0 1  60  1 1 1 0 1 1 
17  0 1 0 0 0 0  39  1 0 0 1 1 0  61  1 1 1 1 0 0 
18  0 1 0 0 0 1  40  1 0 0 1 1 1  62  1 1 1 1 0 1 
19  0 1 0 0 1 0  41  1 0 1 0 0 0   63  1 1 1 1 1 0 
20  0 1 0 0 1 1  42  1 0 1 0 0 1  64  1 1 1 1 1 1 
21  0 1 0 1 0 0  43  1 0 1 0 1 0     
22  0 1 0 1 0 1  44  1 0 1 0 1 1    * = default 
Table 2: Summary of Modbus Data Access Commands 
Function Code (Decimal)  Command Name  
1  Read Discrete Output Status (0xxxx) 
2  Read Discrete Input Status (1xxxx) 
3  Read Output Register (4xxxx) 
4  Read Input Register (3xxxx) 
5  Force Single Coil (0xxxx) 
6  Preset Single Register (4xxxx) 
15  Force Multiple Coils (0xxxx) 
16  Preset Multiple Registers (4xxxx) 
Modbus Plus Card Indicators  
The Modbus Plus card has an indicator that flashes a repetitive pattern to show its network 
communication status, plus two indicators which identify communication errors on the two 
Modbus Plus cable paths. Note that one error indicator will be lit normally in single-cable 
installations, showing that a second cable does not exist. 
Table 3: Modbus Plus Active Indicator Patterns  
Indicator Pattern (Green)  Status 
Six flashes/second  Normal operating state. All nodes on a healthy 
network flash this pattern 
One flash/second  The node is off-line. After being in this state for 5 
seconds, the node attempts to go to its normal 
operating state. 
Two flashes, then OFF for 2 
seconds 
The node detects the network token being passed 
among other nodes, but it never receives the 
token. 
Three flashes, then OFF for 
1.7 seconds 
The node does not detect any token passing on the 
network. 
Four flashes, then OFF for 
1.4 seconds 
The node has detected another node using the 
same address. 









