Summary of the content on the page No. 1
A Sierra Monitor Company
Driver Manual
(Supplement to the FieldServer Instruction Manual)
FS-8700-01 Modbus RTU
&
FS-8700-08 Modbus ASCII
There are several similarities between these two drivers and
we have incorporated them into the same manual to ensure
that our information stays current. Although both drivers
are referenced in this manual, they are different drivers and
need to be ordered separately."
APPLICABILITY & EFFECTIVITY
Effective for all systems ma
Summary of the content on the page No. 2
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Table of Contents Table of Contents 1. Modbus RTU/ Modbus ASCII Description ....................................................................... 3 2. Driver Scope of Supply..................................................................................................... 4 2.1. Supplied by FieldServer Technologies for this driver.................................................... 4 rd 2.2. Provided by Supplier of 3 Party Equipment
Summary of the content on the page No. 3
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 3 of 21 1. Modbus RTU/ Modbus ASCII Description The Modbus RTU and Modbus ASCII drivers allow the FieldServer to transfer data to and from devices over either RS-232 or RS-485 using Modbus RTU or Modbus ASCII protocol respectively. The driver was developed for Modbus Application Protocol Specification V1.1a" from Modbus-IDA. The specification can be found at www.modbus.org. The FieldServer can emulate either a Server or Client.
Summary of the content on the page No. 4
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 4 of 21 2. Driver Scope of Supply 2.1. Supplied by FieldServer Technologies for this driver FIELDSERVER TECHNOLOGIES PART # DESCRIPTION FS-8915-10 UTP cable (7 foot) for RS-232 use FS-8917-02 RJ45 to DB9F connector adapter FS-8917-01 RJ45 to DB25M connection adapter FS-8917-21 RS-485 connection adapter FS-8700-01 (T28700-01) Driver Manual rd 2.2. Provided by Supplier of 3 Party Equipment PART # DESCRIPTION Modbus RTU or Mod
Summary of the content on the page No. 5
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 5 of 21 3. Hardware Connections It is possible to connect a Modbus RTU or Modbus ASCII device to any of the existing serial 1 ports on the FieldServer . These ports simply need to be configured for the appropriate driver in the configuration file. Configure the Modbus RTU or Modbus ASCII device according to manufacturer’s instructions. 1 Not all ports shown are necessarily s
Summary of the content on the page No. 6
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 6 of 21 4. Configuring the FieldServer as a Modbus RTU or Modbus ASCII Client. For a detailed discussion on FieldServer configuration, please refer to the FieldServer Configuration Manual. The information that follows describes how to expand upon the factory defaults provided in the configuration files included with the FieldServer (See “.csv” sample files provided with the FieldServer). This section documents and describes th
Summary of the content on the page No. 7
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 7 of 21 4.2. Client Side Connection Descriptors Section Title Connections Column Title Function Legal Values Specify which port the device is 2 Port P1-P8, R1-R2 connected to the FieldServer 110 – 115200, standard baud Baud* Specify baud rate rates only. 9600 Parity* Specify parity Even, Odd, None Data_Bits* Specify data bits 7, 8 Stop_Bits* Specify stop bits 1 (Vendor limitation) Modbus RTU Modbus _RTU Protocol Spec
Summary of the content on the page No. 8
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 8 of 21 4.3. Client Side Node Descriptors Section Title Nodes Column Title Function Legal Values Up to 32 alphanumeric Node_Name Provide name for Node characters Modbus station address of physical Node_ID 1-255 Server Node Modbus RTU Modbus_RTU Protocol Specify protocol used Modbus ASCII MB_ASCII Specify which port the device is 2 Port P1-P8, R1-R2 connected to the FieldServer Set to Block_Mode if Remote Server Node
Summary of the content on the page No. 9
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 9 of 21 4.4. Client Side Map Descriptors 4.4.1. FieldServer Related Map Descriptor Parameters Column Title Function Legal Values Up to 32 alphanumeric Map_Descriptor_Name Name of this Map Descriptor characters Name of Data Array where data One of the Data Array names Data_Array_Name is to be stored in the FieldServer from “Data Array” section above 0 to maximum specified in “Data Data_Array_Offset Starting location in Data Ar
Summary of the content on the page No. 10
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 10 of 21 4.4.4. Map Descriptor Examples. // Client Side Map Descriptors // Note: All three examples below are addressing the same Modbus registers. // For Nodes where Address_Type is ADU Map_Descriptors Map_Descriptor_Name, Data_Array_Name, Data_Array_Offset, Function, Node_Name, Data_Type, Address, Length, Scan_Interval CMD_AI_01, DA_AI_01, 0, RDBC, MODBUS DEVICE1, Input_Register, 1, 20, 1.000s CMD_AO_01
Summary of the content on the page No. 11
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 11 of 21 5. Configuring the FieldServer as a Modbus RTU or Modbus ASCII Server For a detailed discussion on FieldServer configuration, please refer to the FieldServer Configuration Manual. The information that follows describes how to expand upon the factory defaults provided in the configuration files included with the FieldServer (See “.csv” sample files provided with the FieldServer). This section documents and describes the
Summary of the content on the page No. 12
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 12 of 21 5.2. Server Side Node Descriptors Section Title Nodes Column Title Function Legal Values Node_Name Provide name for Node Up to 32 alphanumeric characters Node_ID Node ID of physical Server Node 1 – 255 Protocol Specify protocol used Modbus RTU 7 Address_Type Specify Register Mapping Model ADU,PDU, -, Modicon_5digit Example Change protocol to MB_ASCII to use Modbus ASCII protocol // Server Side Nodes // For dev
Summary of the content on the page No. 13
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 13 of 21 5.3. Server Side Map Descriptors 5.3.1. FieldServer Specific Map Descriptor Parameters Column Title Function Legal Values Up to 32 alphanumeric Map_Descriptor_Name Name of this Map Descriptor characters Name of Data Array where data One of the Data Array names Data_Array_Name is to be stored in the FieldServer from “Data Array” section above 0 to maximum specified in “Data Data_Array_Offset Starting location in Data
Summary of the content on the page No. 14
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 14 of 21 5.3.3. Map Descriptor Examples // Server Side Map Descriptors where Node Address_Type is ADU // Note: All three examples below are addressing the same Modbus registers. // For Nodes where Address_Type is ADU Map_Descriptors Map_Descriptor_Name Data_Array_Name Data_Array_Offset, Function Node_name, Data_type Address, Length, Data_Array_Low_Scale, Data_Array_High_Scale Node_Low_Scale Node_High_Scale SMD_AI_0
Summary of the content on the page No. 15
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 15 of 21 Appendix A. Advanced Topics – Modbus RTU Appendix A.1. Data Types If Node parameter Address_Type is set as ADU or PDU, then Data_Type must be specified as follows For Address_Type ADU : Address range Data_Type Function Code (Write) Function Code (Read) 1 - 65536 Coil 15 1 1 – 65536 Discrete_Input n/a. 2 1 – 65536 Input_Register n/a. 4 1 - 65536 Holding_Register 16 3 For Address_Type PDU : Address range Data_Type Funct
Summary of the content on the page No. 16
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 16 of 21 Appendix A.2. Single Writes For pure write operations where the function = WRBC or WRBX, the driver defaults to using Function Codes 15 and 16 (Multiple writes). It is possible to force the driver to use Function Codes 5 and 6 (Single Writes) by manipulating the Data_Type parameter as follows: For Address_Type ADU: Address range Data_Type Function Code (Write) 1 - 65536 Single_Coil 5 1 - 65536 Single_Register l 6 For
Summary of the content on the page No. 17
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 17 of 21 Appendix A.4. Managing Floating points with Modbus Modbus as a standard does not support floating point formats. Many vendors have written higher level communications software to use two 16 bit registers to represent floating point or 32 bit integers. This requires conversion software on both ends of the communication channel. The FieldServer supports this function and also provides other options to resolve this issue. Tr
Summary of the content on the page No. 18
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 18 of 21 Transferring 32 bit values with two registers If a Modbus Server sends two consecutive registers to the FieldServer representing either a floating point value or a 32 bit integer value, the FieldServer can combine and decode these registers back into their original format. To do this, the user must read the registers into an integer data array, and then use the Moves function to move the data to a floating point or 32 bit in
Summary of the content on the page No. 19
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 19 of 21 Appendix A.6. Node_Offline_Response This function is specific to the Modbus RTU driver. In systems where data is being collected from multiple Server Nodes and made available on a FieldServer configured as a Modbus RTU Server, when a Server Node goes offline the default behavior of the FieldServer would be to stop responding to polls for this data. This might not be what the user wants. Various options exist making it po
Summary of the content on the page No. 20
FS-8700-01_Modbus_RTU_(T28700-01) Driver Manual Page 20 of 21 Appendix B. Modbus ASCII - Examples of FieldServer setup for typical clients Appendix B.1. FieldServer with GE Cimplicity as client • Run the Cimplicity “Workbench” and create a “New Project” with a unique “Project Name” option of “Basic Control” and protocol “Modbus ASCII”. • Check the project properties and continue with the “Project Wizard Setup” that appears. • Add Modbus port giving it a description. • Create and config
