FS8700-109 – ProtoCessor Complex Protocol – PCP

Driver Version: 1.00

Document Revision: 3

FieldServer Driver – Serial


ProtoCessor Complex Protocol – PCP


The PCP Serial Protocol is designed to achieve the following in a very simple manner:

  • Read a Customer Device’s Database of data objects (We call this process “discovery”)
  • Auto create a Client configuration to read the values/states of the data objects discovered
  • Allow data transfer (read and write) between the Driver and the customer Device
  • Auto create a Server configuration to serve the data to other upstream devices using protocols like Metasys by JCI, Lonworks or BACnet.
  • Determine if the database has changed
  • Of course this is still a standard FieldServer driver and it can be configured manually to read/write data, just like any other driver in the library.


The driver can also be used in a simple mode to poll for specific data from a customer device.  To achieve this, the data objects in the customer device must be known in advance.

The protocol is node-less. This means that messages do not contain source/destination node addresses and hence it would not be possible to differentiate messages from multiple devices on the same connection.  Thus only one node may be defined per connection.

The driver provides both Client and Server emulation. The Server side of the driver is intended to support FieldServer’s Quality Assurance program and is not intended to provide complete emulation of a PCP Server.  Thus the Server side is not fully documented.  At a customer’s request the Server side functionality can be documented and enhanced.  If you are interested in this functionality, then please contact FieldServer’s sales group.


How to get started:

Step 1: Decide on Discovery

Do you want the driver to ‘discover’ your database or will you work with a fixed set of data objects (points). If you have a fixed set of points then the driver can be configured to simply read data from these points.  This saves you the effort of programming your device to respond to the different ‘discovery’ queries the driver will send.

Step 2: Review the protocol specification

The protocol specification document is available from FST. Please request the document named: PS002 – PCP Driver Spec (FS-8700-109).  Read and review the document.

You will need to program your device to respond to the messages sent by the driver. This is done using the serial port API of your device.

If you plan to support ‘discovery’ then program the ability to respond to theses queries sent by the driver.

Poll From ProtoCessor


Poll Object Class Count


Poll Object Class Configuration


Poll Object Class Property


Poll Object Instance Count


Poll Object Instance Info


Configuration Valid / Changed


Irrespective of your decision you will need to program your device to respond to these messages sent by the driver.

Poll From ProtoCessor
11 Read Property Values
12 Read All Property Values
21 Write Propery Values


Step 3: Program your device’s serial port to send responses

Step 4: Configure the driver to do discovery and to read data from your device.


Max Nodes Supported

FieldServer Mode Nodes Comments
Client 1 1 Node per serial port
Server 1 1 Node per serial port


Formal Driver Type


Client and 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: EIA232 or EIA485 (Two wire, Half-Duplex)
Baud Rates: 110; 300; 600; 1200; 2400; 4800; 9600; 19200; 28800; 38400; 57600; 115200 Baud

Default for ProtoCessor is 38400.Data Bits:7,8Stop Bits:1,2Parity:Odd, Even, NoneMultidrop CapabilityNo


Devices tested

Device Tested (FACTORY, SITE)
WattMaster Test device SITE


Connection Notes

This driver is intended for use with a ProtoCessor which has been previously integrated into a customer’s controller.  No additional hardware is required.

Communications functions – Supported functions at a glance:

Request the document named: PS002 – PCP Driver Spec (FS-8700-109) for further information.


Read Operations supported

FieldServer / Protocessor as a Client
Poll Object Class Count Read how many classes customer device has.
Poll Object Class Configuration Read Class Name and Type
Poll Object Class Property Read Class Property Name, Type…
Poll Object Instance Count Read number of instances of specified class
Poll Object Instance Info Read Instance name and other attributes
Configuration Valid / Changed Response indicates if database has changed
Read Property Value / State Property, Class and Instance #’s are specified.
Read all Property Values for a given instance of a class Single command reads all.


Write Operations supported

FieldServer / Protocessor as a Client
Write Property Value / State Property, Class and Instance #’s are specified.


Unsupported Functions and Data Types

Function Reason
Programming messages FieldServer is a data transfer device, and as such, programming messages are not required



Metasys® as used in this document is a trademark of Johnson Controls, Inc.

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