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Chapter 7 · Switching Platform

Datasheet SPM-700401-LC-MF

SPM-700401-LC-MF – IRS product 119788 SPM-700401-LC-MF-P, 4 Single channels, 70A, load mounting panel; hardware version 1.00.

7.1General Description

The SPM-700401-LC-MF is a high current 6HU switching module for use inside IRS Switching Platform mainframes. The module topology provides 4 single load switching channels for max. 70A continuous current with fuse and integrated current transducers in each channel.

The module provides permanent current and temperature monitoring and allows reading of this values via API command.

Internal onboard diagnostic provides a basic functional check of each channel (relay contact, fuse, current transducer) without module removal. The module is controlled by the Switching Platform µController card SPC.

Typical tasks are load and supply switching to DUT. The module is available with a metal panel for load mounting, custom connectors (e.g. for power supply input) can be provided on request.

7.2Safety Instructions

  • Only for use in IRS Switching Platform mainframes (e.g. SP-1200) and within the specified electrical limits.
  • Use only inside suitable 19‘‘-Cabinets and not for applications to humans or animals.
  • Use this SP module only with the SPC-64 µController card and with the SP-Editor SW and its API commands for configuration and control
  • Hot switching is NOT recommended on any circuit of the module. This will reduce the lifetime and maximum switching cycles of the relays and possibly destroy the relays on the module.
  • The module is designed for resistive loads, user has to care about protection circuitry when using inductive or capacitive loads
  • Outputs need sufficient isolation and protection against contact.

7.3Schematic Overview & Pictures

SPM-700401-LC-MF (4 channels each 1 load, MOS-FET switch, 70A, max. 60V): control and switch PCB with MOS-FET, I-transducer, fuse 70A, sense bus relay and diagnostics per channel, load mounting panel with internal loads, external load access and power supply input
SPM-700401-LC-MF-P (with metal load mounting panel)

7.4Scope of Delivery

SPM-700401-LC-MF-P:

  • Switching pcb completely assembled with blank load mounting panel
  • Frontpanel closed, no connector breakouts, no load configuration*

* note: breakout connector and load configuration on request

7.5Certification & Compliance

ItemValue
Certification of conformityCE mark by IRS
RoHS ComplianceEU RoHS directive 2011/65/EU; Directive (EU) 2015/863 Annex II

7.6Used Abbreviations

AbbreviationMeaningDescription
SPSwitching Platforma general term for all Switching Platform products
SPBBackplane InterfaceInterface card for SP Mainframe (e.g. SP-1200)
SPCSwitching Platform Controller3HU µC card that controls a Switching Platform Module
SPMSwitching Platform Module6HU pcb with relays and other circuits controlled by a SPC-64 µController card
SPWSwitching Platform Wiringstandardized cable from a SPM to system interface
DUTDevice Under Testsame as UUT (unit under test)
CTCurrent Transducerinductive current measurement device
HUHeight Unit = 44,45 mm
HPHorizontal Pitch = 5,04 mm

7.7Electrical

7.7.1Load Channel Specification

ItemValueRemarks
Rated Voltage60 Vdcstationary
Rated Current / Channel70 Astationary
Rated Current / Channel85 Atemporary, max. 60sec (1:2 ON/OFF ratio)
Rated Current / Channel100 Atemporary, max. 20sec (1:2 ON/OFF ratio)
VDS (reverse voltage)max. 60 VdcMOSFET
Rds ONmax. 1 mOhmMOSFET
Switching Power (resistive load)100 A @ <60 V-> hot switching does not reduce lifetime of MOSFET
Fuse / Channel70 Avery slow

This values include the complete load channel incl. all components (connectors, pcb routes, fuse, current transducer, ..).

7.7.2MOSFET Specification

The current and voltage ratings of the MOSFET are shown for information only. The “Load Channel Specification“ table shown above has to be used when creating a circuit using this module. The ratings in the “Load Channel Specification“ table are lower than the ratings for the MOSFET by itself.

ItemValueRemarks
Max. Current180 Astationary
Max. Reverse Voltage60 VDC
Leakage current @VGS = 0Vmax. 1 µA@VDSS=60V, Tj = 25°C
Leakage current @VGS = 0Vmax. 100 µA@VDSS=60V, Tj = 125°C
Rds ONmax. 1mOhmMOSFET
Switching Power (resistive load)180A at <60 Vthermal cooling!
Contact Resistancemax. 1 mOhminitial at 1A ID = 100 A
Operating Timetyp. 37 nsVDD 30 V, Vdc 10 V, ID 100 A
Mechanical Lifenot relevantwithout el. load

7.8Mechanical

ItemValueRemarks
Width6 HP= 30,24 mm; standard width (1 slot)
Width12 HP= 60,48 mm; double width (2 slots)
Height6 HU= 266,7 mm
Depth~ 365 mmtotal depth of card incl. front handles and rear side connectors
Weight~ 0,98 kg

7.9Environment

ItemValueRemarks
Operating Temperature Range0..55 °C (32..131 °F)
Operating Humidity Range10-80 %non condensing

7.10Topology & Functions

ItemValueDescription
Nr. of channels4single load channels switched by MOSFET semiconductor
Loads / Channel1loads per channel
Fused Channels4all 4 channels, very slow fuse
Integrated Current Measurementyes, CTcurrent transducer on all 4 channels, not configurable!
Sense 1 connectCh. 1current transducer can connect to Sense Bus 1
Sense 2 connectCh. 2current transducer can connect to Sense Bus 2
Sense 3 connectCh. 3current transducer can connect to Sense Bus 3
Sense 4 connectCh. 4current transducer can connect to Sense Bus 4
Temperature Monitoringyestemperature of all load channels is measured continuously and cooling fans activated in case of overheating
Current Monitoringyescurrent of all channels is continuously measured: error state is set and load channels MOSFET will be switched to open in case of exceeding the current limitation (100A)
Internal Diagnosticyes, current loopInternal diagnostic per test current routed through each channel to check fuse, current transducer and relay contact functionality; incl. report generation
Load Options-PMetal load mounting panel for internal loads
User IDYesVia SP-Editor a user defined identification string will be stored in modules EEPROM (e.g. Load ID, ..)
Memory ObjectsYesVia SP-Editor memory objects can be defined and stored in modules EEPROM (e.g. calibration data, additional module information, ..); max. 6kB
Load Relay Cycle Counteryesswitching cycle of each relay is counted and stored in modules EEPROM; status can be read via SW command
Max. Integrated Load Height<25 mmSPM width = 1 slot (6 HP)
Max. Integrated Load Height<55 mmSPM width = 2 slots (12 HP)

7.11Sense Bus Measurement

7.11.1Shunts & Current Transducers in General

If SP modules provide integrated shunts or current transducers, they are an additional feature to measure the current in a load channel. This current measurement has limited precision and is not a calibrated measurement device.

If required, the user has to care about calibration and precision verification of shunts or current transducers.

7.11.2Sense Bus Topology & Data

The internal 8 wire Sense Busses 1-4 (each Sense+ and Sense-) is located on the complete backplane of the mainframe, connecting all module slots. The 4 sense busses can be connected via 4x SMB sockets on the Backplane Interface card (SPB) to external measurement devices (e.g. to measurement matrix).

On every module inside the mainframe shunts or current transducers (CT) on the load channels can be connected to the Sense Busses 1-4 by closing the corresponding sense relays on the module.

The firmware verifies that only one sense relay is connected to a sense bus at the same time. If already another channel is connected, the API switching function responds an error.

This topology allows in general 4 parallel measurements inside the SP mainframe. Not all load channels can be switched to every sense bus, possible connections are defined in the module’s datasheet.

Using multiple mainframes, the user needs to define if each of the mainframes has a separate sense bus or if they share the same sense bus. Sharing needs to be done outside of the SP mainframe by connecting all sense busses of all mainframes.

ItemValueDescription
Nr. of channels4each channel (Ch.1-4) has an integrated current transducer
Sense Bus Access4x SMB on SPB: core: Sense +, shield: Sense -All 8 sense bus lines can be accessed via Backplane Interface card (SPB) on 4x SMB sockets (isolated mounted)
Sense Bus 1 connect toCh. 1the sense lines of this channel can be switched to Sense-Bus #1
Sense Bus 2 connect toCh. 2the sense lines of this channel can be switched to Sense-Bus #2
Sense Bus 3 connect toCh. 3the sense lines of this channel can be switched to Sense-Bus #3
Sense Bus 4 connect toCh. 4the sense lines of this channel can be switched to Sense-Bus #4
Current Transducer Range± 85ARange of 85A in each direction
Precision at 25°C (77°F)± 0,8% (± 0,20A)total output error (% of IPN) of CT module at 25°C
Precision at 25°C (77°F)± 0,4% (± 0,10A)with autozero function after switching ON
Precision at 85°C (185°F)± 1,3% (± 0,325A)total output error (% of IPN) at 85°C (= max. operating temperature)
Sensitivity50 mV/Aoutput voltage range -4,25V .. +4,25V (+/-85A); e.g. 1A = 50,0 mV; 15A = 0,75V; 85A = 4,25V
Frequency Bandwidth200 kHz+/- 1dB (1kOhm load)
Frequency Bandwidth300 kHz+/- 3dB (1kOhm load)

7.11.3Autozero Function

Each current transducer has an offset on the output voltage when switched supply voltage to ON This happens when switching ON the mainframe or at startup of the complete test system. This offset is constant until the current transducers supply voltage is switched OFF. This happens when switching OFF the mainframe or at shutdown of the complete test system. This offset variation is included in the total output error calculation of the current transducer’s datasheet.

A correction of this constant offset error (for the power ON phase) will improve the precision of the current transducer significant. To eliminate this offset error the SP software provides the API function “Autozero” of channels. This function also is available on the test panel of the module.

The function needs to be executed when the current is definitely “0”, means really no current is detected by the current transducer, e.g. in case the load channel is switched to open.

The recommendation is to use the autozero function minimum on each first run after system started, if it is possible execute autozero in every test sequence run.

7.12Component Location

Component location on the SPM-700401-LC-MF pcb: MOSFETs below the heat sink, current transducers, fuses, sense bus relays, clamps for external temperature sensors, labels, connectors K1 and K2

No.Component
1load channel MOSFET Ch. 1 – Ch. 4 (below heat sink)
2current transducers Ch. 1 – Ch. 4
3Fuse 70A for Ch. 1 – Ch. 4
4Sense Bus relays: Ch.1 to SB1, Ch.2 to SB2, Ch.3 to SB3, Ch.4 to SB4
5Clamps for ext. temperature sensors (MCP9700A)
6Serialnumber and quality check labels

7.13Connectivity

The signal names on each pin of K1, K2 are labeled on the pcb. Pin 1 is always on the top of the connector.

PinK1K2
1Ch. 1Ch. 1
2Ch. 2Ch. 2
3Ch. 3Ch. 3
4Ch. 4Ch. 4
5Com 1Com 1
6Com 2Com 2
7Com 3Com 3
8Com 4Com 4

K1, K2 connector layouts

  • K1: for DUT Adapter / Fixture Interface cabling
  • K2: Load side cabling channels 1-4

For cabling to system’s receiver interface, to DUT Adapter or load wiring following data needs to be considered:

ItemValueRemarks
Max. current76 Aper connector pin
Used pins1pins used per channel and com (return) line
Wire cross sectionsAWG 8 / 10,0 mm²per load channel and com wire

7.14SP-Editor Software

The Switching Platform Editor SW is installed on the system controller. It provides setup, configuration, information and diagnostic functions for the complete Switching Platform topology in the system.

For most functions the login level “Developer” is required. In delivery state there is no password for “Developer” defined.

SP Editor with marked access level button and Change Access Level dialog

For slot- and module specific configuration and functions:

Start Switching Platform Editor SW – (1) login as developer – (2) load project configuration file or add new mainframe with autodetect – (3) connect SP mainframe – (4) select slot with module – (5) select “Slot Config” Tab and requested functional group – (6) select requested function

SP Editor with steps 1 to 6 for slot and module specific functions

7.14.1ADC Test Panel

The SPM-700401-LC-MF provides an ADC test panel for the module’s onboard sensors measuring pcb temperature and load path current. The current transducers constant offset can be eliminated by autozero function to improve precision. The test panel can be opened parallel to a test sequence and can be used for debugging purposes.

SP-Editor running with login as developer and loaded project configuration, SP mainframe connected – (1) select slot with SPM-700401-LC-MF module – (2) select “Slot Config” Tab and “ADC” – (3) select “Test Panel”

ADC test panel of the SPM-700401-LC-MF with load channel currents LC1 to LC4 and temperatures T1 to T3

The ADC Test Panel provides temperature and load path current monitoring:

  • (4) set practical size and # of columns for panel and show or hide left parameter list
  • (5) Activate “Live” for monitoring values and select update rate (200ms .. 3s)
  • (5) Call Action “Autozero” for resetting the current transducers permanent offset and improve current measurement precision. Note: load current needs to be “0A” to work correctly. Temperature sensors are not affected by autozero function.
  • (6) Monitoring of 4x load channels current value and 3x temperature values

7.14.2Relay Test Panel

The SPM-700401-LC-MF provides a switching test panel for two main purposes:

  • manual switching of relays and MOSFETs for debugging
  • monitoring switching states parallel to automated sequences

SP-Editor running with login as developer and loaded project configuration, SP mainframe connected – (1) select slot with SPM-700401-LC-MF module – (2) select “Slot Config” Tab and “Relay” – (3) select “Test Panel”

Relay test panel of the SPM-700401-LC-MF with load channels LC1 to LC4 and sense bus relays

The Relay Test Panel provides monitoring and also manual switching of all accessible relays on the module:

  • (4) set practical size and # of columns for panel
  • (5) Activate “Live” for monitoring values and select update rate (200ms .. 3s)
  • (6) Switching and monitoring of 4x load channel MOSFET and 4x sense bus relays. Relay channels are closed/opened by clicking, closed channels are highlighted in green color

7.14.3Diagnostic & Selftest

The SPM-700401-LC-MF provides an internal selftest sequence that verifies open and close state of load relays and functionality of fuses, current transducers and temperature sensors. After performing the selftest sequence a report is generated that can be stored by user for documentation purposes.

SP-Editor running with login as developer and loaded project configuration, SP mainframe connected – (1) select slot with SPM-700401-LC-MF module – (2) select “Slot Config” Tab and “Relay” – (3) select “Selftest”

Selftest window of the SP Editor with test execution report

  • (4) The blue arrow starts the selftest, a safety warning will be displayed before start
  • (5) After execution the report is shown directly including all teststeps, results and limits. The report can be stored for documentation with the disc icon

7.14.4Equipment Protection Function

As a high current switching module, the SPM-700401-LC-MF is continuously measuring and controlling the 6 load path currents and the 3 pcb temperature sensors. The firmware provides different protection functions when sensor values exceed defined levels.

Overtemperature Protection:

ItemValueDescription
Temp. Sensor5 kS/sSample rate of temperature signal
Temp. Sensor> 60 °CActivate fan request flag for SP mainframe, 6x bottom fans are switched ON; mainframe will increase internal cooling by air stream of ~ 900 m³/hour for min. 30 seconds

Overcurrent Protection:

ItemValueDescription
Load Channel Current5 kS/sSample rate of current signal
Load Channel Current> 100 A; < -100 AAverage of 1.000 samples exceeds this range: 1. Load Channel will be switched to open state; 2. Request Error State flag for the SP mainframe. Error State relay will switch to open state and interrupt interlocking loop of power supplies or el. loads (if connected). Firmware will raise error state for complete system, each switching request will be answered with error response. Requires acknowledge of error state via SW command to reset this error state

7.15Sparepart List

Manufacturer / SupplierPart Nr.IRS Part Nr.Component Description
LEMCASR25-NP119072Current transducer with IPN = 25A
LittelfuseBF1 series 70A118478Fuse 70A, very slow
PanasonicAGN20024105776Sense-Bus relay
Phoenix ContactSPC 16/ 8-STF-10,16107926Load panel connector 8 pin
Phoenix ContactFMC 1,5/ 3-ST-3,81109438Load panel connector 3 pin
MicrochipMCP9700A-E/TO118483Temperature Sensor Load Panel

7.16Product Support

Documents and downloads

Further documents and files for your IRS product are available on myIRS.

Go to downloads