The SCADA IEC870-5-101 driver implements communication with IEDs (Intelligent Electronic Devices), RTUs (Remote Terminal Units), and IO devices compatible with this protocol. This allows it to act as a master station.
Communication Driver Name: IEC8705101
Current Version: 2014.2
Implementation DLL: T.ProtocolDriver.IEC8705101.dll
Protocol: IEC-870-5-101 Master standard protocol
Interface: TCP/IP or Serial
IEDs types supported: Any IED compatible with IEC-60870-5-101
Communication block size: Maximum 250 bytes, FT 1.2 format
Protocol Options: Number of octets used by a link layer, application layer, data objects, and transmission cause
Multi-threading: User defined. Five threads per node by default
Max number of nodes: User defined
PC Hardware requirements: Standard PC Ethernet interface board, RS485, or RS232 port
In SCADA, each Object Data type has three variants, one without a timestamp and two that have a timestamp (23 bits and 56 bits). By default, users do not have to specify the variants that will be used. This is processed in a transparent way.
The IEC-60870-5-101 protocol is implemented in master mode where it communicates with IEDs that implement the IEC-870-5-101 protocol slave. The frame used for the data exchange is FT 1.2, non-balanced (slave does not send unsolicited data). There is a large range of settings options that are used to match different usage profiles.
Master has the following operating sequence:
On start or Communication Failure
Infinity Loop
CommonAddress Num Octets – The number of bytes used for the address of the application layer in the targeted slave station. It can be 1 or 2 bytes
LinkAddress Num Octets – The number of bytes used for the address of the link layer in the targeted slave station. It can be 1 or 2 bytes
ObjectAddress Num Octets – The number of bytes used for the address of the data object. It can be 1, 2, or 3 bytes
CauseOfTransmission Num Octets – The number of bytes used to show the cause of the data transmission. It can be 1 or 2 bytes
Serial:
TCP/IP channels:
Each node is a Server station (IED). Many nodes can be associated to each channel
TCP/IP Communication:
Serial:
Common Address = The address of the IED's application layer
LinkAddress = The address of the IED's link layer
Synchronism sample time = A period of time, in milliseconds, between two consecutive submissions of Date/Time and remote IEDs. Zero is used to indicate that there is no need for synchronization. Note that IEDs that are synchronized by GPS should not be synchronized by the master
General Interrogation (GI) sample time = A period of time, in milliseconds, between two consecutive submissions of general interrogation requests and an IED. The IED responds by sending blocks of information. It sends as many as are required to send all points
Status sample time = A length of time, in milliseconds, between two consecutive requests for changes that occur in class 1 and class 2 points. The IED responds by sending blocks of information. It sends as many as are needed to show the changes occurred. Normally, this period should be set to a short value. For example,1000 milliseconds
General Counters Sample Time = A general timer for counter requests, in milliseconds. The IED responds with as many information blocks as necessary
Clock Adjust = This should be enabled if the Master Station needs to be synchronized by remote/slave IED date/hour. This is useful if the remote/slave IED is synchronized by GPS
Backup Station =The same settings made to the main station can be made to one backup workstation (an alternative IED) if there is one in the facility
Points can be input or output. Input points are acquired by the protocol and have basically two main parameters: point type and address. Output points are used for remote controls and have an additional parameter used to specify the type of output operation. In a given IED, point addresses are unique.
IEC870-5-101 provides a groups of Points feature. In this implementation, they are not considered. Instead, there is a general read considering all points, and a general counters read considering all timers.
This implementation supports two standard classes:
Note that the concepts of class and point differ from each other. Thus, a given point, that has a changed state, could generate a class 1 even that should be processed before the next class 2 reading. To avoid inconsistencies, only class 2 cyclical readings of point can trigger a change in point status on SCADA. Class 1 events solely generate SCADA events.
The Master communication mode implements:
The point types were implemented according to the following:
M_SP_NA: 1 - Single-point information
M_DP_NA: 3 - Double-point information
M_ST_NA: 5 - Step position
M_BO_NA: 7 - Bitstring with 32 bits
M_ME_NA: 9 - Measured value, normalized
M_ME_NB: 11 - Measured value, scaled value
M_ME_NC: 13 - Measured value short floating point
M_IT_NA: 15 - Integrated totals
M_EP_TA: 17 - Equipment protection with Time
C_SC_NA: 45 - Single command
C_DC_NA: 46 - Double command
C_RC_NA: 47 - Regulating step command
C_SE_NA: 48 - Set point command, normalized value
C_SE_NC: 50 - Set point command, short floating point value
The “Information Object Address” is the address field that is filled in when registering a point. It is a number that is 2 or 3 bytes long, as chosen in the “Protocol Options.” Two bytes are most commonly used for this number, so the range is from 0 to 65535. It must be unique for the given IED. These addresses are set by the IED manufacturer.
The command parameter is used as a code of one byte, which details the command type to be executed into a remote IED. When the user registers a point typed as command output, this field appears, and the user can fill it in. If the code is already known, the user can just type it into the field. If not, click on the button on the right side of this field to display a window with the available actions and details.
The code generated by choosing the items in the parameter setting command window is obtained by calculating the sum of two parts (A and B). The first part indicates the action, and the second part indicated the details of the transaction, as defined below:
For Single Command C_SC_NA:
For Double Command C_DC_NA:
For Voltage Regulation C_RC_NA:
The remaining options are the Select Command (select the device that will be controlled) or the Execute Command (send the proper action command). The select command option adds 128 to the code obtained from the sum of the A and B parts.
Example: Code = 9 in a simple command means Long Pulse to Turn on the remote device.
In Slave mode, the Access Type field should be set as indicated below:
For reading points:
The Access Type must be set as:
For command points:
The Access Type must be set as: