Siemens SED2-MODBUS2 Technical Instructions

Technical Instructions

Modbus RTU Interface Module for SED2

Document No. 155-767

February 25, 2009

Description

Product Part Number
Contents

Required Tools

The Modbus RTU Interface Module for SED2 enables serial communication
between a Modbus RTU and a SED2 Variable Frequency Drive (VFD).

SED2-MODBUS2

• MicroGate II Interface module.

• Local cable for USS communication with SED2.

• Network cable for ModBus communication with Building Automation

controller.

• Installation documentation.

Personal computer for configuring device prior to operation.

Configuration Kit (SED2-MODBUS2_KIT), containing:

• External Power Supply for the MicroGate II.

• 9-pin (female) to 9-pin (female) Serial Null Modem Cable.

• Installation documentation.

NOTE: Both the Interface Module and the SED2 must be configured prior to

operation.

Figure 1.

Siemens Industry, Inc.

Technical Instructions Modbus RTU Interface Module for SED2

Equipment damage, or loss of data may occur if

WARNING:

Document Number 155-767
February 25, 2009

Warning/Caution Notations

WARNING:

Personal injury/loss of life may occur if you do not
perform a procedure as specified.

Hardware Setup

Power Supply

Programming Switch

CAUTION:

you do not follow procedure as specified

Power may be supplied by either connecting the configuration kit power supply to one side of
the unit, or by providing regulated 6 to 28 Vdc power to pin 9 of the local serial port from the
SED2. See Figure 2.

Do not connect the external 9 Vdc power supply and pin 9
of the LOCAL cable at the same time.

The Programming (PRG) Switch on the Interface Module, should always be in the RUN
position (up) for normal operations and configuration.

The PRG position is used strictly for loading firmware at the factory.
The Interface Module comes with two serial ports. See Figure 2.
The LOCAL port is for connection to a SED2 and supports both RS232 and RS485 (2-wire

and ground) communications. The LOCAL port is also used for configuration and
programming of the Interface Module.

The NETWORK port is for connection to a network and supports RS485 (2-wire)
communications.

Figure 2. Interface Module Hardware.

Page 2 Siemens Industry, Inc.

Modbus RTU Interface Module for SED2 Technical Instructions

A four wire cable (Figure 5) connects the LOCAL port on the Interface Module to an

Document Number 155-767
February 25, 2009

Hardware Setup, Continued

The Interface Module is provided with two cables.
A three wire cable (Figure 3) connects the NETWORK port to a network. Because the

network connection type may vary among different installations, the cable ends are
stripped wires to provide maximum flexibility.

Figure 3. Three Wire
Network Cable.

Figure 4. RS485 Network Cable.

SED2. The cable ends in stripped wires to facilitate a connection to the SED2 drive
terminals shown below.

CAUTION:

SED2 drive power should be off while connecting
the wires to the drive terminals.

Figure 5. Four Wire
Local Port Cable.

Figure 6. SED2 Drive Cable.

Figure 7. Cables Installed on Interface Module.

Siemens Industry, Inc. Page 3

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009

Hardware Setup,
Continued

LED Indicators

There are a total of three bi-color LED indicators on the Interface Module. See
Figure 8. The NET LED displays communications activity on the Network (Modbus)
port.

• The STAT LED displays the overall status of the Interface Module.

• The LCL LED displays communications activity on the Local (SED2) port.

During normal operations, the NET and LCL LEDs will quickly alternate red and green
flashes, making it look almost amber; this is normal.

Table 1. Interface Module General Status LED (Stat).

For this state: LED is: To indicate:

No power Off No power applied to the device.

Run Mode

Configuration Mode

Fatal Error

Flashing Green
(250 ms On, 250 ms Off)

Flashing Green
(1.5 sec on, 1.5 sec Off)

Flashing Yellow
(250 ms On, 250 ms Off)

Interface Module is operating
normally in RUN Mode.

Interface Module is in
CONFIGURATION Mode.

Interface Module has
experienced a fatal error, and
has halted communication.

Figure 8.

NOTE: If the Interface Module has been installed correctly, the STAT LED will be

flashing green, and the LCL LED will be alternating so fast between red and
green that it will appear to be glowing amber.

Table 2. Network Communication Activity LED (NET).

For this state: LED is: To indicate:

Received Data Red Data from the Modbus Network.

Transmit Data Green Data onto the Modbus Network.

Table 3. SED2 Communications Activity LED (LCL).

For this state: LED is: To indicate:

Received Data Red Data from the SED2.

Transmit Data Green Data to the SED2.

Page 4 Siemens Industry, Inc.

Modbus RTU Interface Module for SED2 Technical Instructions

Interface Module ASCII

Interface Module RTU

Interface Module

RTU

Interface

Module ID

115200 bps

7
8

None

Odd

1
2

Document Number 155-767
February 25, 2009

Hardware Setup
Continued

Default Configuration

Parameter Options Default

Protocol

Table 4. Configuration Options.

1… 254 2

1200 bps
4800 bps
9600 bps

Baud Rate

9600 bps

19200 bps

9600 bps

38400 bps
57600 bps

Changing the
Configuration

Data Bits

Parity

Even

Stop Bits

8

Even

1

The configuration stored in the Interface Module may be changed from the default
configuration by entering CONFIGURATION Mode.

1. Attach a configuration cable between the LOCAL port and a serial port on a
computer.

2. Start a terminal program, such as HyperTerminal, on the computer, and connect
using the following setting:

• Baud = 9600 bps

• Data bits = 8

• Parity = None

• Stop bits = 1

• Flow control = None

Siemens Industry, Inc. Page 5

3. With the Programming Switch set to RUN, apply power to the Interface Module,
and press the ENTER key within five seconds of startup. See Figure 9.

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009

Changing the
Configuration,
Continued

Once the Interface Module is in CONFIGURATION Mode, it will send its current
configuration to the terminal program.

Figure 9. MicroGate II Configuration Di splay.

Table 5. Keyboard Navigation.

Use the UP and DOWN arrows, on the computer
keyboard, to navigate to the field you want to change.

Change values with the LEFT and RIGHT arrows.

Save Configuration Navigate to here and press ENTER to save changes.

Page 6 Siemens Industry, Inc.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009

SED2 Parameter
Configuration

Table 6. SED2 Parameter Settings to Communicate with the MicroGate II.

The Interface Module communicates with the SED2 VFD using the USS protocol
and the following parameter configuration:

• USS address set to 0

• USS baud rate set to 19.2K

• Parity set to Even

• Number of data bits set to 8

Configure SED2 VFD parameters to communicate with the MicroGate II, per Table 3.

SED2

Parameter

P0003 User Access Level 3 (Expert Level)
P0700[0] Command Source
P1000[0] Frequency Setpoint

P2009[0] USS Normalization 0 (Disabled)
P2010[0] USS Baud Rate 7 (19.2K baud)
P2011[0] USS Address 0

P2014[0] USS telegram off time

P2041[0] Protocol Selection for

Function Setting/Value

5 if Starting/Stopping VFD from Modbus;
otherwise, DO NOT change.

5 if Setting the Frequency from Modbus;

Source

RS485 port

otherwise, DO NOT change.

0 to Disable the USS Watchdog timer.
100 or greater to enable the USS Watchdog

timer.
NOTE: Do not set to a value from 1 to 99.

0 (USS Protocol)

Siemens Industry, Inc. Page 7

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009

Watchdog Timer
Setup

To enable an Interface Module Host Watchdog Function, the Interface Module Master
controls the first two holding Registers, WDOG TIME (40001) and WDOG ACTION
(40002).

When the Host Watchdog Function activates, the

Interface Module does not receive any

further communications from the Master for a period of time determined by WDOG
TIME (40001). With WDOG ACTION (40002) set to 1, the SED2 stops on loss of
communications.

To activate the

Interface Module Host Watchdog Function, set:

• WDOG TIME (40001) to the amount of time in milliseconds that must pass
with no further

Interface Module communications.

• WDOG ACTION (40002) to 1 so that the SED2 stops on loss of
communications with the Modbus master.

To deactivate the
SED2 Parameter 2014, USS Telegram Off Time, controls a Watchdog timer function for

Interface Module Host Watchdog Function, set WDOG ACTION to 0.

the USS port.

• Once the

Interface Module stops communicating with the SED2, the SED2 automatically

Interface Module establishes communications with the SED2, if the

enters the fault state with a F0070 fault number.

• Parameter P2014 specifies the timeout value for the USS Watchdog timer

function.

If P2014 is set to 0, the USS Watchdog timer is disabled. If P2014 is set to a non-zero
value, the USS Watchdog timer function is enabled and the timeout value is the P2014
non-zero value.

If using the USS Watchdog timer function with the Interface Module, set P2014 to a
value of 100 or greater so that accidental faults do not occur because of normal
communications dela ys between the Inter f ac e Modu le and the SED 2.

Page 8 Siemens Industry, Inc.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009

Verifying the
Installation

After all necessary connections have been made, power up the SED2 and the
Interface Module. Wait approximately five seconds.

Modbus Interface
Module with
Network a s
Command Source

Modbus Interface
Module with
Network a s
Command Source

NOTE: If the Interface Module has been installed correctly, the STAT LED will

be flashing green, and the LCL LED will be alternating so fast between
red and green that it will appear to be glowing amber.

If not using the Modbus for commands, do not change P0700[0] and P1000[0].
Instead, verify communications by issuing a start command (from the source) and
checking the feedback on the Modbus master device to ensure that it reads proper
values in the appropriate Registers.

1. To verify that the Interface Module and SED2 are set up correctly, set P0700[0]
and P1000[0] to a value of 5 so that the SED2 can be controlled from the
Interface Module network.

2. From the Interface Module host, issue an Interface Module write, with of a value
of 8192 (2000h, or 50% of the maximum frequency) to the FREQ REF register
(40003 followed by a Modbus write with the value of 1 to the ENABLE register
(40004).

3. Write a value of 1 to the CMD START register to stop the drive again. The SED2
frequency can be changed at any time during this process by writing to the
FREQ REF register (40003).

Siemens Industry, Inc. Page 9

Technical Instructions Modbus RTU Interface Module for SED2

Interface Module

Document Number 155-767
February 25, 2009

Registers

The following tables contain the lists of all Interface Module holding Registers available
on the Interface Module. The Interface Module host may write to Registers 40001
through 40023. All other Registers are read only.

There is a scaling factor included for some of the Registers. Because Modbus does not
represent floating point numbers, all floating point values in the drive are converted to
integer register values by applying a scaling (multiplication) factor. The scaling factors
are in the range of 10 to 1000.

For example: ACCEL TIME has a scaling factor of 100. If the SED2 contains a
value of 20.50, then the ACCEL TIME register will contain a value of 2050.

FREQ REF (40003) and FREQ ACTUAL (40063) are special case Registers. FREQ
REF contains the raw integer value passed in the HSW portion of a USS protocol
request to the SED2 drive. FREQ Actual contains the raw integer value passed in the
HIW portion of a USS protocol response from the SED2. Both Registers are scaled so
that a value of 4000th represents 100% of the actual frequency.

FREQ SCALED (40044) contains a scaled version of the HIW data, so that a value of
2000 in the register represents the value 4000h in the USS protocol response (and
100% of the maximum frequency).

STW and HSW refer to the 1st and 2nd control words, respectively, of PZD data
included in every poll sent from the Interface Module to the SED2 drive via the USS
protocol. ZSW and HIW refer to the 1st and 2nd status words, respectively, of PZD data
included in every poll response from the SED2 drive to the Interface Module via the USS
protocol. Registers mapped to PZD data are updated frequently.

All other parameters (except WDOG ACTION and WDOG TIME), which are handled
internally in the Interface Module, are mapped to parameters in the SED2 drive, and are
updated cyclically.

• Registers mapped to monitor parameters—
such as CURRENT or SPEED, whose values change automatically during
normal operation of the drive, without the intervention of an operator—are
updated at a rate of approximately once per second.

• Registers mapped to setup parameters—such as ACCEL TIME or FREQ
MAX, whose values typically change only via intervention by an operator—are
updated at a rate of approximately once every five seconds.

Page 10 Siemens Industry, Inc.

Modbus RTU Interface Module for SED2 Technical Instructions

40001

WDOG TIME

MS

1

0 – 65535

––

40002

WDOG ACTION

––

1

STOP DRIVE

NO ACTION

––

40003

FREQ REF

PCT

100

0.00 – 4000h (4000h = 100%)

HSW

40005

CMD FWD REV

–– 1 REV

FWD

STW:11

40006

CMD START

–– 1 START

OFF

STW:0

40007

FAULT ACK

–– 1 ACK

NO ACK

STW:7

40009

ENABLE PID

–– 1 ENABLE

DISABLE

P2200

40010

CURRENT LMT

PCT

10

10.0 – 400.0

P0640

40011

ACCEL TIME

SEC

100

0.00 – 650.00

P1120

40013

HAND AUTO

–– 1 HAND

AUTO

P0718

40014

DIGITAL OUT 1

–– 1 ON

OFF

P0731

40015

DIGITAL OUT 2

–– 1 ON

OFF

P0732

40017

PID UP LMT

PCT

10

-200.00 – 200.00

P2291

40018

PID LO LMT

PCT

10

-200.00 – 200.00

P2292

40019

P GAIN

––

1000

0.000 – 65.000

P2280

40021

D GAIN

––

1

0 – 60

P2274

40022

FEEDBK GAIN

PCT

100

0.00 – 500.00

P2269

40023

LOW PASS

––

100

0.00 – 60.00

P2265

40025

SPEED

RPM 1 -16250 – 16250

r0022

40026

CURRENT

A

10

0 – 1638.3

r0027

40027

TORQUE

NM

10

-3250.0 – 3250.0

r0031

40029

TOTAL KWH

KWH 1 0 – 65535

r0039

40030

DC BUS VOLTS

V

1

0 – 65535

r0026

40031

REFERENCE

Hz

10

-650.0 – 650.0

r0020

Document Number 155-767
February 25, 2009

Interface Module Registers, Continued

Table 7. Interface Module Registers.

Register

Number

Description Units Scaling Factor On Text Off Text SED2

Or Range

Reference

40004 RUN ENABLE –– 1 ENABLE OFF STW:3

40008 PID SETP REF PCT 10 -200.0 – 200.0 P2240

40012 DECEL TIME SEC 100 0.00 – 650.00 P1121

40016 FREQ MAX HZ 100 1.00 – 650.00 P2000

40020 I GAIN SEC 1 0 – 60 P2285

40024 FREQ OUTPUT HZ 10 -650.0 – 650.0 r0024

40028 ACTUAL PWR KW 100 0 – 655.35 r0032

40032 RATED PWR KW 100 0 – 655.35 r0206

Page 11 Siemens Industry, Inc.

Technical Instructions Modbus RTU Interface Module for SED2

Siemens Indus try, Inc.

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Document No. 155-767

40033

OUTPUT VOLTS

V 1 0 – 65535

r0025

40034

40035

STOP RUN

––

1

STOP

RUN

ZSW:2

40036

40037

CONTROL MODE

––

1

SERIAL

LOCAL

ZSW:9

40038

ENABLED

–– 1 ON

OFF

ZSW:0

40039

40040

ANALOG IN 1

PCT

10

-300.0 – 300.0

r0754/0

40041

40042

ANALOG OUT 1

PCT

10

-100.0 – 100.0

r0774/0

40043

ANALOG OUT 2

PCT

10

-100.0 – 100.0

r0774/1

40044

40045

PID SETP OUT

PCT

10

-100.0 – 100.0

r2250

40046

40047

PI FEEDBACK

PCT

10

-100.0 – 100.0

r2266

40048

DIGITAL IN 1

–– 1 ON

OFF

r0722:0

40049

40050

DIGITAL IN 3

–– 1 ON

OFF

r0722:2

40051

40052

DIGITAL IN 5

–– 1 ON

OFF

r0722:4

40053

DIGITAL IN 6

–– 1 ON

OFF

r0722:5

40054

40055

LAST FAULT

–– 1 0 – 65535

r0947

40056

1ST FAULT

–– 1 0 – 65535

r0947

40058

3RD FAULT

–– 1 0 – 65535

r0947

40059

WARNING

––

1

WARN

OK

ZSW:7

40060

LAST WARNING

–– 1 0 – 65535

r2110

40062

DRIVE MODEL

–– 1 0 – 655.35

r0200

40063

Document Number 155-767
February 25, 2009

Interface Module Registers, Continued

Table 8. Interface Module Registers.

Register

Number

Description Units Scaling

Factor

FWD REV –– 1 FWD REV ZSW:14

AT MAX FREQ –– 1 MAX NO ZSW:10

READU TO RUN –– 1 READY OFF ZSW:1

ANALOG IN 2 PCT 10 -300.0 – 300.0 r0754/1

FREQ ACTUAL PCT 10 00.0 – 100.0 HIW

PID OUTPUT PCT 10 -100.0 – 100.0 r2294

DIGITAL IN 2 –– 1 ON OFF r0722:1

On Text Off Text SED2

Or Range

Reference

DIGITAL IN 4 –– 1 ON OFF r0722:3

FAULT –– 1 FAULT OK ZSW:3

40057 2ND FAULT –– 1 0 – 65535 r0947

40061

INVERTER VER –– 100 0.00 – 655.35 r0018

FREQ ACTUAL –– 1 0 – 4000h (4000H = 100%) HIW

Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as
design improvements are introduced. Product or company names mentioned herein may be the trademarks of their respective owners.
© 2009 Siemens Industry, Inc.

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