FS-8704-13 – GE – Service Request Transfer Protocol (SRTP)

Driver Version: 1.02

Document Revision: 2

FieldServer Driver


GE – Service Request Transfer Protocol (SRTP)



The GE-SRTP driver allows the FieldServer to transfer data to and from devices over Ethernet using GE-SRTP Driver protocol. Almost all GE automation equipment supports the GE-SRTP protocol when equipped with an Ethernet Port.

The FieldServer can emulate either a Server or Client. The driver, acting as a Client, is capable of reading and writing system memory of any number of remote SRTP capable devices. The FieldServer can scale word data ( %AQ, %AI, %R ) when acting as a Client.

When configured to act as an SRTP Server, the driver accepts system messages which write to system memory and responds to read requests. When acting as a Server the driver is always at privilege level 4 (allowing it to be written and read).

The driver cannot emulate a Client and Server simultaneously on the same connection to the same IP address.

The driver is capable of exposing its communication statistics so that they can be monitored by a downstream device. Driver diagnostics & statistics are exposed in the FieldServer data arrays so they may be read and monitored by remote devices / systems.

Write through and port expander modes are supported.

The driver has been timed reading 5700 bytes of table data per second.

The IC697CMM742 Ethernet module supports both GE SRTP and GE EGD.


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



Compatibility Matrix

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


Connection Information

Connection type: Ethernet

Ethernet Speeds Supported

10Base-T, 100Base-T[1]


Proprietary Physical Interfaces Supported

FieldServer Model Adapter Model # Vendor Physical Medium


Devices tested

Device Tested (FACTORY, SITE)
All GE Ethernet Capable devices – includes Series 90-30, Series 90-70, Versamax and a number of GE Drives. 90-30 CPU 313 with CMM321 (Nov 2001).


Connection configurations


Connection Notes

Ensure that the device IP_address is configured to be on the same IP network as on the FieldServer.

Communications functions – Supported functions at a glance:

Data Types Supported

%R Register memory %AI Analog Input Memory
%AQ Analog output memory %I Discrete input memory
%Q Discrete output memory %T Discrete temporary memory
%M Discrete momentary memory %SA Discrete system memory group A
%SB Discrete system memory group B %SC Discrete system memory group C
%S Discrete system memory %G Discrete global data table


Unsupported Functions and Data Types

Function Reason
Programming messages FieldServer is a data transfer device, and as such, programming messages are not required
The driver supports only a limited set of Service Requests and PDU’s.


[1] Not all FieldServer models support 100BaseT.  Consult the appropriate instruction manual for details of the Ethernet speed supported by specific hardware.

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