IEC 60870-5-101 and IEC 60870-5-104
With the IEC 60870-5 protocols, a Saia PCD® system can act as remote unit (RTU) for telecontrol applications like Power Plants controls, Energy, Gas and Water distribution. Because of its high reliability and efficiency, these protocols are also involved in many other industrial application fields including pumping stations, waste water treatment, tunnel supervision and even remote building control. Both companion standards IEC 60870-5-101 (serial lines) and IEC 60870-5-104 (TCP/IP) are available and can even run in the same system.

A Saia PCD® driver version with Monitor functions is available for IEC 60870-5-104 on request.

Fupla The driver is delivered in form of an FBox library. FBoxes include not only the data points definition but all related mechanisms like:
  • PCD clock settings
  • General interrogation, global or groups
  • Transmission of events on value change
  • Pulse commands
  • Select Before Operate
  • Value conversions
  • Background scan
IL An FB call is also available to add user specific messages directly in the event buffer. This allows you to program your own event detection and stamping, for instance in a subsystem connected over S-Bus.
Wide Area Control The IEC 60870-5-104 can also be used over GPRS modem, for instance with the Wide Area Controllers. This configuration is particularly interesting for pump stations.

In case of large configurations, the data point definition is made in an Microsoft Excel file, compiled by the NG-Configurator and linked to the Saia PCD® program. This method ensures a good overview of the configuration and an efficient edition tool. The same file can include different standard configurations (e.g. A, B, C, up to Z) that can be quickly selected and recompiled.




On request, the Interoperability Checklist is available for the both versions of the IEC drivers. Find below an extract from the interoperability checklist as short list of the supported features.


Feature IEC 60870-5-101 IEC 60870-5-104
Public line modem / ISDN / GSM Yes N/A
Baudrates 1200 to 115kbds Yes N/A
Balanced transmission (Full duplex) Yes Yes
Unbalanced transmission (Master-Slave) Yes N/A
Redundant connections (not simultaneous) No Yes
Number of Connections per group
(per redundant driver)
N/A 2
Maximum number of simultaneous drivers
(simple or redundant)
1 10

Maximum number of data points (NT-Systems).

To be reduced with coexistance of a user application.

3000 4000
Event buffer size (adjustable) 100, 300, 1000 100, 300, 1000, 10'000
Process information in monitor direction, with or without timetag:
- Single-point information
- Double-point information
- Step position information
- Bitstring of 32 bit
- Measured value, normalized value (relative float)
- Scaled value (integer 16bits)
- Measured value, short floating point value
- Integrated totals (counters)
Yes Yes
Format conversion included
(Integer, Float, Normalized, Raw values)
No Yes
Sequence of elements and objects Yes No
Command transmission, Direct command Yes Yes
Activation and Termination confirmation Yes Yes
Select-Execute sequence / Select Before Operate Yes1) Yes
Process information in control direction:
- Single command (persistent or pulse)
- Double command  (persistent or pulse)
- Regulating step command
- Bitstring of 32 bit
- Set point command, normalized value
- Set point command, scaled value
- Set point command, short floating point value
Yes Yes
Fast Event détections, up to 1ms, handled by interrupt. No Yes
Clock Synchronization Yes2) Yes2)
Use UTC or Local time Local UTC or Local
General Interrogation, General or Group Yes Yes
Counter Interrogation, General or Group Yes Yes
Counter Freeze / Counter Reset Yes3) Yes3)
Read procedure No Yes
Backgroud scan No Yes
File transfer No No


1) With IEC 60870-5-101 driver, the Select-Execute sequence is supported but cannot be made mandatory and does not time out.
2) Clock synchronization is supported but milliseconds are not warranteed.
3) Depending on the user application counter reset may not be possible with this command

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