GE EP-5261 User manual

RSTI-EP Slice I/O
Serial Communication Module EP-5261
Function Block FB_RSTI_EP_5261
Handling Function Block FB_MBM_RTU_Master
Serial Communication Module EP-5261
Serial Communication Module EP-5261
The RSTi-EP Serial Communication (EP-5261) module provides extended
communication options. For example, devices (such as barcode scanners or
printers) can be integrated consistently in RSTi-EP systems using an RS-232,
RS-485, or RS-422 interface. The EP-5261 module presents a solution for
connecting the control cabinet to the field.
The data transfer rate can be parameterised between 300 and 11,5200 bps.
The process data length can be parameterised to be 8 or 16 byte. A
terminating resistor can be parameterised for the RS-485 and RS-422
interface respectively.
The communication status is indicated by two LEDs on the respective plug.
The module electronics supply the connected data terminal device with
power from the input current path (IIN) either with 5 V dc or 24 V dc. Both
supply voltage outputs are protected against over-current.
The module features a type plate, which includes identification information,
the key technical specifications, and a block diagram. Additionally, a QR code
allows for direct online access to the associated documentation. The
software for reading the QR code must support inverted QR codes.
Markers are available as accessories for labelling the equipment. Each I/O
module can be labelled to ensure clear identification when replacing
individual modules or electronic units.
The RSTi-EP station is usually installed on a horizontally positioned DIN-rail.
Installation on vertically positioned DIN rails is also possible.
Modules should to be allowed to de-energize for a minimum 10 seconds after
power down, prior to starting any maintenance activity.
Refer to the RSTi-EP Slice I/O User Manual (GFK-2958) for additional
information.
For power-feed (a software utility available on PME V9.00) requirements, refer
to the RSTi-EP Power Supply Reference Guide.
EP-5261 Module Features
•Spring style technology for ease of wiring
•DIN-rail mounted
•Double-click installation for positive indication of correct installation
•Supports indirect firmware update through the network monitor
•Supports replacement without shutting down the system
GFK-2992B
September 2016
© 2016 General Electric Company.
*Indicates a trademark of General Electric Company and/or its subsidiaries. All other trademarks are the property of their respective owners.

2RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Ordering Information
Module Description
EP-5261 RSTi-EP Slice I/O Serial Communication module
Specifications
Item EP-5261 Specification
System Data
Data
Process, parameter, and diagnostic data depend on the network adapter used
Interface
RSTi-EP system bus
System bus transfer rate
48 Mbps
Serial Interfaces
Number
1
Type
RS-232, RS-485, RS-422,
parameterisable
Transfer Rate
300 – 11,5200 Bps, parameterisable
Supply voltage
5 V dc or 24 V dc
Current of power supply output
500 mA max
Standards RS232
DIN 66020, DIN 66259, EIA-RS232C, CCITT V.24 / V.28
Standards RS485/RS422 DIN 66259 part 1 and 3, EIA-RS422/485, CCITT V.11
Terminating resistor
RS485/RS422
120 Ω, parameterisable
Short-circuit-proof
Yes
Module diagnosis
Yes
Individual channel diagnosis
Yes
Supply
Supply voltage
20.4 V – 28.8 V
Current consumption from
system current path ISYS
8 mA
Current consumption from input
current path IIN
16 mA + Load
General Data
Operating temperature
-20 to +60°C (-4 to +140 °F)
Storage temperature
-40 to +85°C (-40 to +185 °F)
Air humidity (operation/transport)
5 to 95%, noncondensing as per IEC 61131-2
Width
11.5 mm (0.45 in)
Depth
76 mm (2.99 in)
Height
120 mm (4.72 in)
Weight
92 g (3.25 oz)
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 3
GFK-2992B
Current Demand for Analog Output Modules
Product
I
SYS
I
IN
I
OUT
I
S
I
L
EP-5261
8 mA
16 mA + Load
--
--
--
I
SYS
IIN
IOUT
IS
IL
x
Current consumption from the system current path
Power consumption from input current path
Power consumption from output current path
Current demand of the connected sensors
Current demand of the connected actuators
Must be included when calculating the power supply
LEDs
LED
EP-5261 Status
Module
Status
Green: Communication over the system bus
Red: Collective error diagnostic
1.1 Yellow:RS-232 parameterised
Yellow flashing:Data is being received
1.2 Yellow:RS-232 parameterised
Yellow flashing:Data is being transmitted
1.3
--
1.4
--
2.1
--
2.2
--
2.3
--
2.4
--
3.1
3.1 - 3.4 Yellow: RS-422 parameterised
3.1 + 3.2 Off, 3.3 + 3.4 Yellow: RS-485 parameterised
3.2
3.3
Yellow flashing: Data are being recieved
3.4
Yellow flashing: Data are being transmitted
4.1
Green: Supply voltage +5 V dc
4.2
--
4.3
Green: Supply voltage +24 V dc
4.4
--
For public disclosure

4RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Overview of Editable Parameters
Description
Options1
Default
Operating mode
Disabled (0) / RS232 (1) / RS485 (2) / RS422 (3)
Disabled
Data bits2
7 Bit (0) / 8 Bit (1)
8 Bit
Baud rate
300 (0) / 600 (1) / 1200 (2) / 2400 (3) / 4800 (4) / 9600 (5) / 14400 (6) /
19200 (7) / 28800 (8) / 38400 (9) / 57600 (10) / 115200 (11) 9600
Stop bit
1 Bit (0) / 2 Bit (1)
1 Bit
Parity
None (0) / Even (1) / Odd (2)
None
Flow control
None (0) / CTS/RTS (1) / XON/XOFF (2)
None
XON character
0 ... 255
17
XOFF character
0 ... 255
19
Terminating resistor
RS-485/422 Off (0) / On (1) Off
Process data length
16 Byte (1)
16 Byte
1) Values in brackets for EtherCAT and Modbus-TCP
2) Option 7 Bit works only in combination with a parity (even or odd)
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 5
GFK-2992B
Diagnostic Data
Name
Bytes
Bit
Description
Default
Error indicator 0
0
Module error
1
Internal error
2
External error
3
Channel error
0
4
Error
5
Reserved
0
6
Reserved
0
7
Parameter error
Module type 1
0
Module Type 0x05
1
1
0
2
1
3
0
4
Reserved
0
5
Reserved
0
6
Reserved
0
7
Reserved
0
Error byte 2
2
0-7
Reserved
0
Error byte 3 3
0-2
Reserved
0
3
Internal diagnostic FIFO full
0
4-7
Reserved
0
Channel type 4
0
Channel type 0x79
1
1
0
2
0
3
1
4
1
5
1
6
1
7
0
Diagnostic bits per
channel 5 Number of diagnostic bit per channel 0
Number of channels
6
Number of similar channels per module
1
Channel error
7-10
0-31
Reserved
0
Time stamp
43-46
Time stamp [μs] (32 bit)
For public disclosure

6RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Data Transfer
The process data length can be parameterized to be 8 or 16 Bytes. Byte 0 is used for status and diagnosis, Byte 1 for the
data segment length, and the remaining 6 or 14 Bytes are user data.
Process input data: The data sent from the serial device are written into the receive memory of the module. As soon as
the SPS request results in that RX_CNT is not equal RX_CNT_ACK, the data will be sent in segments via the fieldbus
coupler to the PLC. The successfully data transfer will be acknowledged to the module.
The receive memory can safe a maximum of 255 Bytes. A software handshake (XON/XOFF) or a hardware handshake
(RTS/CTS) can be parameterised using the flow control, so that an alarm will warn against a buffer overflow.
Process output data: The data sent from the PLC via the fieldbus coupler are written into the transmission memory of
the module. The module is continously checking if data is ready to be sent or a data transfer to the device has
completed successfully. Not until then will the next data will be transferred.
Process Input Data
Byte
Format
Name
Bit
Description
Notes
IB0 Word Status and
Diagnosis
IX0.0 Data in the receive
memory
RX = 0: Receive memory is empty
RX = 1: A telegram or telegram
segment in the receive memory is
ready for transmission.
IX0.1 Receive memory
nearly full
Only 10 characters are left in the
receive memory. XOFF will be set if
parametrerised.
IX0.2
Not used
IX0.3 RX_CNT
The RX_CNT value is assigned to each
data segment of the process input
data while transmission. The sequence
or the RX_CNT values is:
Binary: 00, 01, 10, 11, 00, ...
Decimal: 0, 1, 2, 3, 0, ...
A faulty data seqence indicates
missing data segments.
IX0.4 RX_CNT
IX0.5 TX_CNT_ACK
The TX_CNT_ACK value is a copy of the
TX_CNT value, which has been
transferred together with the last data
segment of the process output data.
TX_CNT_ACK acknowledges that the
data has been taken over successfully.
IX0.6 TX_CNT_ACK
IX0.7 STAT
STAT = 1: Communication with the
device is without fault.
STAT = 0: Faulty communication with
the device.
IB1 Word
Length of the
data segment
/ of the
subsequent
diagnosis data
RX Length of the data / diagnosis data in
this frame
IB 2 ... IB
7
or
IB 2 ... IB
15
Received data
User data of the
transferred telegram
segment
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 7
GFK-2992B
Process Output Data
Byte
Format
Name
Bit
Description
Remarks
QB0 Word Status and
Diagnosis
IX0.0 RXBUF FLUSH
Bit 0: RXBUF FLUSH
The receive memory can be scrubbed using
this bit.
STATRES = 1: A requirement with RXBUF FLUSH
= 1 will be ignored.
STATRES = 0: The receive memory will be
scrubbed with RXBUF FLUSH = 1.
IX0.1 TXBUF FLUSH
Bit 1: TXBUF FLUSH
The emission memory can be scrubbed using
this bit.
STATRES = 1: A requirement with TXBUF FLUSH
= 1 will be ignored.
STATRES = 0: The emission memory will be
scrubbed with TXBUF FLUSH = 1.
IX0.2 RX_HWBUFFER
Bit 2: DisableSend_TX_HWBUFFER
This bit controls the hardware emission
memory:
DisableSend_TX_HWBUFFER = 0: The hardware
emission memory is released. A character
(Byte) will be sent as soon as it reaches the
buffer.
DisableSend_TX_HWBUFFER = 1: The hardware
emission memory is locked. Characters (Bytes)
will only be sent, when
DisableSend_TX_HWBUFFER is set to 0 again.
IX0.3 TX_CNT
The TX_CNT value is assigned to each data
segment of the process output data. The
sequence or the TX_CNT values is:
Binary: 00–>01–>10–>11–>00...
Decimal: 0–>1–>2–>3–>0...
A faulty data sequence indicates missing data
segments.
IX0.4 TX_CNT
IX0.5 RX_CNT_ACK
RX_CNT_ACK must include a copy of the
RX_CNT value. The RX_CNT value has been
transferred together with the last data
segment of the process input data.
RX_CNT_ACK must be set in analogy with
RX_CNT (in the status byte). It indicates that the
data segment has been transferred
successfully by using RX_CNT and enables to
receive new data.
IX0.6 RX_CNT_ACK
IX0.7 Communication
Status
The input data status bit STAT will be reset
using this bit. When changing from 1 to 0
(falling edge) STAT will be reset from 0 to 1.
STAT = 0: All changes in the data fields
TX_BYTE_CNT, TX_CNT and RX_CNT_ACK will be
ignored. The receive or emission memory can
be scrubbed using RXBUF FLUSH or TXBUF
FLUSH respectively.
STAT = 1 or changing from 0 to 1: The buffers
cannot be scrubbed.
QB1 Word
Length of the
data segment
QB 2 ... QB 7
or
QB 2 ... QB 15
Transmission
data
User data of the
transferred
telegram segment
For public disclosure

8RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Enabling the Data Transfer
There are ways to announce the communication module to the control. Using the test mode, you only copy
the input data into the output data of the module so the received data will be sent again. Or, select one of the
function blocks provided by your engineering tool. For programming, refer to the following schemes
showing the sequences for receiving and transmission.
SPS application error
Segment-sequence error
Scheme of the Receiving Sequence Scheme of the Transmission Sequence
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 9
GFK-2992B
The status and control word values during various states of communication are provided in the following table.
Action
Input Byte 0 (Status) of Module
Input
Byte 1
(length
of RX
byte
seg.)
Output byte 0 (control) off the module
Output
byte 1
(length
of TX
byte
seg.)
Notes
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
Stat TX_CNT_ACK RX_CNT STATRES RX_CNT_ACK TX_CNT
Init/
Startup 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
After
powerup,
module is
ready for
communi-
cation
Activate
communi-
cation
1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0
PLC is
ready for
communi-
cation
(response)
Receive
data
1 0 0 0 1 0 0 0 N
(1 ..14) 1 0 0 0 0 0 0 0 0
Module
has
received
bytes
1 0 0 0 1 0 0 0 N 1 0 1 0 0 0 0 0 0
RX
acknow-
ledge after
data taken
over
Send
data
1 0 0 0 1 0 0 0 X 1 0 1 0 1 0 0 0 N
(1..14)
Before
changing
TX-CNT, set
TX bytes
1 0 1 0 1 0 0 0 X 1 0 1 0 1 0 0 0 N
TX
acknow-
ledge after
module
sent data
For public disclosure

10 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Field Wiring
The connection frame can take up to four connectors (shown in the following figure), and four wires can be connected
to each connector. The Spring style technology allows either finely stranded or solid wire conductors with crimped wire-
end ferrules or ultrasonically welded wires, each with a maximum cross-section of 1.5 mm² (16 guage), to be inserted
easily through the opening in the clamping terminal without having to use tools. To insert fine stranded wires without
wire-end ferrules, the pusher must be pressed in with a screwdriver and released to latch the wire.
Connector Block with Four Wire Connectors
Connector Specifications:
•Conductor cross-section 0.14 to 1.5 mm² (26 – 16 guage)
•10 A max amperes
•4-pole
The modules do not have a fused sensor/activator power supply. All cables to the connected sensors/actuators must be
fused corresponding to their conductor cross-sections (as per Standard DIN EN 60204-1, section 12).
Connection Cables for the Serial Device
Use shielded cables, because electromagnetic interferences from the surroundings have to be assumed. The maximum
permissable cable length depends on the cable capacitance and the baud rate.
Connecting a RS-232 Device
Maximum Cable Length RS-232
Cable Capacitance
Maximum Cable Length
≤ 2500 pF
15 m (49 ft), shielded
55 pF/m
45 m (147 ft)
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 11
GFK-2992B
Connecting RS-485 or RS-422 Device
The serial device must be connected using a twisted pair cable (U/UTP, Type Cat- 3 or J-2YY-2x2x0,6).
Maximum Cable Length RS-422/485
Baud Rate in kbps
Maximum Cable Length
≤ 19200
1200 m (3937 ft), shielded
38400
500 m (1640 ft)
57600
250 m (820 ft)
115200
200 m (656 ft)
•RS-485: Use one core pair for Data+/Data–; use any wire for the ground singal GND COM. The remaining free
wires should be connected to ground.
•RS-422: Connect the wires for transmitting signals TXD+/TXD– and those for receiving signals RXD+/RXD– in
pairs respectively. Use any wire for the ground singal GND COM. The remaining free wires should be connected
to ground.
Refer to the RSTi-EP Slice I/O User Manual (GFK-2958) for additional information.
Technical assistance is available at http://support.ge-ip.com.
Installation in Hazardous Areas
EQUIPMENT LABELED WITH REFERENCE TO CLASS I, GROUPS A, B, C & D, DIV. 2 HAZARDOUS AREAS IS SUITABLE FOR USE IN
CLASS I, DIVISION 2, GROUPS A, B, C, D OR NON-HAZARDOUS AREAS ONLY
WARNING - EXPLOSION HAZARD - SUBSTITUTION OF COMPONENTS MAY IMPAIR SUITABILITY FOR CLASS I, DIVISION 2;
WARNING - EXPLOSION HAZARD - WHEN IN HAZARDOUS AREAS, TURN OFF POWER BEFORE REPLACING OR WIRING
MODULES; AND
WARNING - EXPLOSION HAZARD - DO NOT CONNECT OR DISCONNECT EQUIPMENT UNLESS POWER HAS BEEN
SWITCHED OFF OR THE AREA IS KNOWN TO BE NONHAZARDOUS.
ATEX Marking
II 3 G Ex nA IIC T4 Gc
Ta: -20 to +60°C (-4 to +140 °F)
For public disclosure

12 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Connection Diagrams
EP-5261 Module Connections
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 13
GFK-2992B
Connection Block Diagrams
RS232 RXD
RS232 TXD
RS232 RTS
RS232 CTS
RS485/422 RXD+
RS485/422 RXD-
RS422 TXD+
RS422 TXD-
5 V
GND
24 V
GND COM
EP-5261 Block Diagram
For public disclosure

14 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
Function Blocks for Enabling Serial Communication
The serial communication module uses 8 registers of input memory and 8 registers of output memory to send and
receive the data to any serial device. Function blocks are provided as part of the toolchest drawer to enable faster
implementation of serial communication with less efforts on application development.
Toolchest Structure
Note: The toolchest drawer is available for download from the support site at http://geautomation.com.
The function block FB_RSTI_EP_5261 is used to send and receive byte strings of length upto 400 bytes. The function
block can send 400 bytes of data and receive 400 bytes of data. The length of the data to be received and sent is
determined by the input parameter of the function block.
The function block FB_MBM_RTU_Master is used to send and receive Modbus messages with the support of the
FB_RSTI_EP_5261 function block. The RTU master function block reads the user inputs and creates Modbus messages.
Tthe byte string is then input to the function block FB_RSTI_EP_5261 which in turn outputs the bytes on the serial bus.
The response is received by FB_RSTI_EP_5261 and passed as input to the RTU master to parse the response and update
the data to internal controller memory.
The function block ModbusMaster_CoilMax is internally used by the RTU master function block.
Note: Refer to the respective function block section in this document for more information on input and output
parameters of the serial and RTU master function blocks.
The blocks Serial_Comm and Serial_Comm_wMBMRTU are pre-defined blocks that call to FB_RSTI_EP_5261 and
FB_MBM_RTU_Master. Additionally, the symbolic variables are assigned to the inputs and outputs of the function blocks
FB_RSTI_EP_5261 and FB_MBM_RTU_Master.
To invoke serial and RTU master functions blocks
If only serial communication is required for the application, perform the following steps:
1. Import the UDT Ser_Data to the controller target.
2. Import the block FB_RSTI_EP_5261 to the controller target.
3. Import the block Serial_Comm.
4. Call the block Serial_Comm in the application logic.
If Modbus RTU communication is to be used,
1. Import the UDT’s Ser_Data and MBM_Data into the controller target.
2. Import the blocks in the following sequence as follows:
a. ModbusMaster_CoilMax
b. FB_MBM_RTU_Master
c. FB_RSTI_EP_5261
d. Serial_Comm_wMBMRTU
3. Call the block Serial_Comm_wMBMRTU in the application logic.
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 15
GFK-2992B
Function Block FB_RSTi_EP-5261
Function Block FB_RSTI_EP_5261
The RSTi-EP Function Block (FB_RSTI_EP_5261) can be used for the data
handling of the serial interface module RSTi EP-5261 (1 Channel Serial
Communications, RS-232, 422, 485). It supports simultaneous transmitting
and receiving of data (full duplex mode). For example, using RS-232 mode is
possible. As only the input and output data is evaluated, this block can be
chosen regardless of the type of interface used.
To enable data transmission using FB_RSTI_EP_5261, a User Defined Type
Ser_Data must be imported.
Additionally, each array must to be limited to 400 bytes. To use the variables,
an instance of this UDT must be built.
The FB_RSTI_EP_5261 block retrieves the process input data (such as
InputOfModule, %AI0001) and stores it on the data buffer (RxDataBuffer) of a
UDT. The size and the location of the data buffer are user-determined.
Additionally, the user can define the number of bytes within a telegram
(uiMaxRecvData). The same process applies for data transmission.
For public disclosure

16 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
FB_RSTi_EP-5261 Input Variables
Variable
Type
Description
xEnableRecv
BOOL
Enables receive data: 0 = Receive disabled, 1 = Receive enabled
xEnableSend
BOOL
Enables send data: 0 = Send disabled, 1 = Send enabled
xQuit
BOOL
Acknowledgement of errors
xClr_Buf_Rx
BOOL
Flushes receive buffer : 0 to 1 and Quit = 1
xClr_Buf_Tx
BOOL
Flushes the send buffer : 0 to 1 and Quit = 1
xDisableTxHWBuffer
BOOL
Disables the hardware (HW) transmit buffer: 0 = released , 1 = disabled
uiMaxRecvData UINT
Maximum number of the data byte to be received within one telegram. Can be
changed before a new job according to the expected telegram length.
Note: Must be > 0. If not, data will not be received.
uiMaxSendData UINT
Maximum number of the data byte to be transmitted within one telegram. Can be
changed before a new job according to the expected telegram length.
Note: Must be > 0. If not, data will not be transmitted.
InputOfModule ARRAY [0..7] OF INT
Process input data of the module . Data type is INT.
OutputOfModule ARRAY [0..7] OF INT
Process input data of the module. Data type is INT.
RxDataBuffer ARRAY OF BYTE
Address of the buffer that receives data within the PLC. Array of n elements of
data type BYTE. Currently fixed to 400 bytes.
TxDataBuffer ARRAY OF BYTE
Address of the buffer that transmits data within the PLC. Array of n elements of
data type BYTE. Currently fixed to 400 bytes.
FB_RSTi_EP-5261 Output Variables
Variable
Type
Description
xBusyRecv
BOOL
Displays an active data reception
xRecvDone
BOOL
Displays finished data reception. Remains TRUE until xEnableRecv is TRUE.
uiRecvDataCnt
UINT
Counter for the received data bytes
xBusySend
BOOL
Displays active data transmission
xSendDone
BOOL
Displays finished data transmission. Remains TRUE until xEnableSend is TRUE.
uiSendDataCnt
UINT
Counter for transmitted data bytes
xRxHWBufNotEmpty
BOOL
Indicates that the hardware receive buffer is not empty
xErrorFlag
BOOL
Displays a general error. Can be reset by acknowledging the variable xQuit.
wRetVal
WORD
Return Value: value is > 8000h to error
Possible Output
Variable
RetVal Description
Warnings
16#0000
No error
16#0001
Receive buffer not empty
16#0002
Handshake (CTS or XOFF) ON
16#0003
Receive buffer not empty and handshake (CTS or XOFF) ON
Errors
16#8000
Module not ready for communication. Check the address of variable InputOfMdule.
16#8008
Indicates a parameter fault. Check the parameter choice in the PLC configuration.
16#8010
Indicates a hardware fault. Replace the hardware.
16#8020
Indicates fault data flow control. Check the parameter in the PLC configuration.
16#8040
Indicates frame fault. Check the parameter choise in the PLC configuration.
16#8080
Indicates (receive)buffer overflow of EP-5261 module. Check the communication.
16#80C0
Indicates (receive)buffer overflow and frame fault of EP-5261 module. Check the
communication.
16#8101
Size of receive buffer is > maximum number of received bytes ==> FB abort.
16#8201
Size of send buffer is > maximum number of bytes to be sent ==> FB abort.
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 17
GFK-2992B
Modbus RTU Master Function Block (FB_MBM_RTU_Master)
The modbus RTU master function block FB_MBM_RTU_Master is a MODBUS RTU Master block used in combination with
the Serial Communication Interface module RTSi EP-5261 and the function block FB_RSTI_EP_5261. Using this block, a
maximum of 120 registers / 1024 coils per job per message can be exchanged.
Modbus RTU Master Function Block (FB_MBM_RTU_Master)
For public disclosure

18 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
To enable MODBUS data access, a User Defined Types MBM_Data must be imported.
To use the variables, an instance of this UDT must be built.
Every data transfer on the bus is initiated and controlled by the master. A high level on the input varible xMODfcStrobe
starts the job, and its function is determined by the function code entered at the input variable usiMODfc.
Communication with the MODBUS station, for which an address has been parameterized on the input variable
usiMODslaveAdr, is accepted. Depending on the function code, the MODBUS input parameters are interpreted as listed
in the following table.
Function
Code
uiMODdatOff uiMODdatNr warMODRegister xarMODCoil
FC 1 Coil source offset in slave
Number of requested
coils
---
Coil target buffer in
master
FC 2
Input source offset in
slave
Number of requested
inputs
---
Input target buffer in
master
FC 3
Holding register source
offset in slave
Number of requested
registers
Holding register target
buffer in master
---
FC 4
Input register source
offset in slave
Number of requested
registers
Input register target
buffer in master
---
FC 5
Coil target offset in slave
---
---
Coil value in index [1]
FC 6
Holding register target
offset in slave
--- Register value in index [1] ---
FC 8
---
---
Test value in index [1]
---
FC 15 Coil target offset in slave Number of coils to be sent ---
Coil source buffer in
master
FC 16
Holding register target
offset in slave
Number of registers to be
sent
Holding register source
buffer in master
---
Buffers warMODRegister and xarMODCoil are always Read or Written by the master from the first index (MODBUS to 1).
The MODBUS diagnostic outputs usi_MODslaveAdrDone, usiMODfcDone, uiMODdatOffDone, and uiMODdatNrDone,
always mirror the communication state during a malfunction, meaning they acknowledge the respective inputs or
provide information concerning the content of the slave response. With function codes 5, 6 and 8, uiMODdatNrDone
describes the written value. The output xMODtransActive is TRUE during execution, until the slave response is received.
After the job has been completed, the output returns to FALSE and xMODtransOk is set to a value of 1 if no telegram
fault, protocol fault, data fault, or other communication fault has occurred. During a fault, xMODtransOk remains at
FALSE and the fault is described with the usiMODfailCode exception code. If the slave does not answer within the set
tMODtimeOut timeout threshold, an error message is generated. The outputs are refreshed each time a new job is
started.
For public disclosure

RSTi-EP Slice I/O Serial Communication Module 19
GFK-2992B
Supported Function Codes
Function
Code
Description Output
1
Read multiple coil status
Reading of bit variables (Coils)
2
Read multiple input status
Reading of bit variables (Inputs)
3
Read multiple holding registers
Reading of word variables (Register)
4
Read multiple input registers
Reading of word variables (Inputs)
5
Force single coil
Writing of a bit variable
6
Force single register
Writing of a word variable
8
Loop back diagnostic test (00: return query data)
Connection test
15
Force multiple coils
Writing multiple bit variables (Coils)
16
Force multiple registers
Writing multiple word variables (Register)
FB_MBM_RTU_Master Input Variables
Variable
Type
Description
xEnable BOOL
Enable COM port for MODBUS communication and reset/initiate the module EP-
5261 while toggle the flag.
usiMODSlaveAdr
BYTE
Address of MODBUS Slave. Default = 0.
usiMODfc BYTE
Function codes
1, 2, 3, 4, 5, 6, 8, 15, 16 are supported, depending of the MODBUS slave
uiMODdatOff
WORD
Offset address (begin) of MODBUS register that will be accessed
uiMODdatNr
WORD
Number of MODBUS register of the access
tMODtimeOut
TIME
Timeout for MODBUS slave answer. Default = 10s, value in second.
xMODfcStrobe
BOOL
Start of a MODBUS request 0 to 1
xRxBusy
BOOL
Responding bit of FB_RSTI_EP_5261: Receive action is active
xRxDone
BOOL
Responding bit of FB_RSTI_EP_5261: Receive action is done
uiRxByteNo
WORD
Responding CNT of FB_RSTI_EP_5261: Received byte count
xTxBusy
BOOL
Responding bit of FB_RSTI_EP_5261: Send action is active
xTxDone
BOOL
Responding bit of FB_RSTI_EP_5261: Send action is done
uiTxByteNo
WORD
Responding CNT of FB_RSTI_EP_5261: Send byte count
xRxBufferNotEmpty
BOOL
Responding bit of FB_RSTI_EP_5261: RxHWBuffer not empty
wRetVal
WORD
Responding state of FB_RSTI_EP_5261 RetVal of FB_RSTI_EP_5261
FB_MBM_RTU_Master Input/Output Variables
Variable
Type
Description
warMODRegister
Array 0..120 of
WORD
MODBUS data: Buffer for receive or send register, such as
MBM_Data01.arwMB_Register.
xarMODCoil
Array 0..1023 of
BOOL
MODBUS data: Buffer for receive or send BOOL(coil) variables, such as
MBM_Data01.arxMB_Coil.
bInputbuffer Array 0..270 of
BYTE
Responding data base of FB_RSTI_EP_5261: Address of the buffer for
receives data within the PLC. Array of 400 elements of data type BYTE,
such as myUDT01.arbRecvData.
bOutputbuffer Array 0..270 of
BYTE
Responding data base of FB_RSTI_EP_5261: Address of the buffer for the
transmit data within the PLC. Array of 400 elements of data type BYTE,
such as myUDT01.arbSendData.
For public disclosure

20 RSTi-EP Slice I/O Serial Communication Module
GFK-2992B
FB_MBM_RTU_Master Output Variables
Variable
Type
Description
xMBMasterFirstCycle
BOOL
Flag first cycle: set to a value of 1 after the first cycle
xComPortActiv
BOOL
Status of COMport, MODBUS is activated
xMODtransActive
BOOL
MODBUS transmission is active
xMODtransOk
BOOL
MODBUS request is answered OK
usiMODslaveAdrDone
BYTE
Last addressed MODBUS slave
usiMODfcDone
BYTE
Last Function Code
uiMODdatOffDone
WORD
Last offset addr. of MODBUS register
uiMODdatNrDone
WORD
Last number of MODBUS register
usiMODfailCode
BYTE
MODBUS fail code
xEnableRx
BOOL
Responding Bit of FB_RSTI_EP_5261: Start/Enable Receive
xEnableTx
BOOL
Responding Bit of FB_RSTI_EP_5261: Start/Enable Send
xQuitt
BOOL
Responding Bit of FB_RSTI_EP_5261: Error acknowledge
TXBUF_FLUSH
BOOL
Responding Bit of FB_RSTI_EP_5261 flush the transmit buffer of RST- EP-5261
RXBUF_FLUSH
BOOL
Responding Bit of FB_RSTI_EP_5261: flush the receive buffer of RSTi EP-5261
TXBUF_DISABLE
BOOL
Responding Bit of FB_RSTI_EP_5261: Disable Tx hard buffer
RX_BYTECNT
WORD
Responding CNT of FB_RSTI_EP_5261: Byte counter of received bytes of RSTi EP-
5261
TX_BYTECNT
WORD
Responding CNT of FB_RSTI_EP_5261: Byte counter of transmitted bytes of RSTi
EP-5261
Possible Output
Variable
usiMODfailCode Description
Error code
0
No error
1
MODBUS: Illegal Function Code
2
MODBUS: Error Data address
3
MODBUS: Error Data value
4
MODBUS: Error telegram length
10
Parameter error of the function block
11
COMport open/initializing failed
12
MODBUS: CRC Error
13
MODBUS: Time out
14
MODBUS: Error slave address
15
MODBUS: Slave indicates incorect Function Code
16
MODBUS: Slave indicates incorrect number or address of register
Note: FB_MBM_RTU_Master uses and calls the auxiliary function block ModbusMaster_CoilMax (included in the library).
For public disclosure