PLC Communication Modules

Showing 1 - 24 of 234 products

$612.00

Only 2 units left

Product
Article Number (Market Facing Number)	6DD16881AC0
Product Description	* SPARE PART* SIMADYN D INTERFACE SUBMODULE SS3 SERIAL INTERFACE I/O 485
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	Not available
Commodity Code	85049099
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.018 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1682-0CE3 Siemens

$2,394.75

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16820CE3 \| 6DD16820CE3
Product Description	* SPARE PART* SIMADYN D SUBRACK SR24.3 115/230V AC INTEGRATED FAN 24 SLOTS , L- AND C-BUS
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643270174
Commodity Code	85381000
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	15.432 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1606-0AD0 Siemens

$2,510.73

Only 8 units left

Product
Article Number (Market Facing Number)	6DD16060AD0 \| 6DD16060AD0
Product Description	*Spare part* SIMADYN D Technology module T400 for 6SE70/71 and SRT400 32 Bit/32MHz, 8BE, 2BA, 4BE/BA 5AE, 2 AO, 2 pulse encoder inputs 2SER.INTERFACE+1SSI-encoder or 1SER.INTERFACE+2SSI-encoder Configurable with D7-SYS 1MB Flash, 2MB RAM, 32KB EEPROM
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643034691
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	1.032 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1610-0AK0 Siemens

$3,934.82

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16100AK0 \| 6DD16100AK0
Product Description	* SPARE PART* SIMADYN D FLASH MEMORY MODULE MS51 PCMCIA CARD FOR PM4. PM5. PM6 4 MB FLASH-EPROM, 8KB EEPROM
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643265118
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.101 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1682-0DA1 Siemens

$0.00

Sold Out

Product
Article Number (Market Facing Number)	6DD16820DA1 \| 6DD16820DA1
Product Description	SIMATIC TDC Slot cover SR51
Product family	Ordering Data Overview
Product Lifecycle (PLM)	PM400:Announcement of product phase-out
Additional Product Information
EAN	4025515739838
UPC	662643297072
Commodity Code	85389099
LKZ_FDB/ CatalogID	ST.DA99
Product Group	2310
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.882 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1640-0AH0 Siemens

$6,083.43

Only 3 units left

Product
Article Number (Market Facing Number)	6DD16400AH0 \| 6DD16400AH0
Product Description	SIMATIC TDC Signal module SM500 with 8 AO/8 AI/16 DO/16 DI/ 4 incremental encoder inputs/ 4 absolute value encoder inputs/ 6 LEDs
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	4019169134774
UPC	Not available
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST.DA99
Product Group	4476
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	1.230 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD2920-0AL0 Siemens

$15,710.92

Only 4 units left

BRAND NEW CONDITION, GUARANTEED.

Siemens 6DD1607-0AA0 Siemens

$1,174.50

Only 9 units left

Product
Article Number (Market Facing Number)	6DD16070AA0 \| 6DD16070AA0
Product Description	* SPARE PART* SIMATIC S7-400, FM 458 APPLICATION MODULE FOR SIMATIC S7-400
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643265583
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4100
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	2.562 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1600-0BA1 Siemens

$4,469.23

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16000BA1
Product Description	*Spare part* SIMATIC TDC CPU551 64-bit processor module with digital inputs
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	4019169134743
UPC	662643297652
Commodity Code	85371091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4476
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	1.129 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1682-0CD0 Siemens

$2,527.06

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16820CD0 \| 6DD16820CD0
Product Description	* SPARE PART* SIMADYN D SUBRACK SR12.2 24V DC NATURAL CONVECTION 12 SLOTS , L- AND C-BUS
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643399325
Commodity Code	85381000
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	17.637 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1672-0AB0 Siemens

$2,232.95

Only 4 units left

Buy the Siemens 6DD1672-0AB0 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD1672-0AB0 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1661-0AD1 Siemens

$8,290.72

In stock, 11 units

Product
Article Number (Market Facing Number)	6DD16610AD1 \| 6DD16610AD1
Product Description	SIMATIC TDC communications module CP50M1 with 8 MB buffer module up to 1 MPI, up to 2 PROFIBUS DP interfaces
Product family	CP50M1 communications module
Product Lifecycle (PLM)	PM400:Announcement of product phase-out
Additional Product Information
EAN	4019169149099
UPC	662643297096
Commodity Code	85176200
LKZ_FDB/ CatalogID	ST.DA99
Product Group	2310
Group Code	R132
Country of origin	Germany
SCIP number	6166b95f-3ded-4cbd-ac58-546c5a36f145
Delivery information
Net Weight (lb)	0.002 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD2920-0AR6 Siemens

$600.00

Only 1 unit left

PLC Direct is not an authorized distributor. We offer a broad range of in-stock products with minimal lead time.

Siemens 6DD1681-0AH1 Siemens

$1,160.00

Only 2 units left

Product
Article Number (Market Facing Number)	6DD16810AH1
Product Description	SIMADYN D INTERFACE MODULE SE7.1 8AI/AO, +-10V
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	Not available
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4315
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.395 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1682-0CF0 Siemens

$1,886.27

Only 2 units left

Product
Article Number (Market Facing Number)	6DD16820CF0
Product Description	* SPARE PART* SIMADYN D SUBRACK SRT 115/230V AC NATURAL CONVECTION 2 SLOTS , PT10 AND CS51
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	Not available
Commodity Code	85389099
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	9.612 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD7021-0AA0 Siemens

$0.00

Sold Out

Buy the Siemens 6DD7021-0AA0 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD7021-0AA0 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1688-0AD0 Siemens

$927.23

Only 9 units left

Product
Article Number (Market Facing Number)	6DD16880AD0 \| 6DD16880AD0
Product Description	* SPARE PART* SIMADYN D COMMUNICATION SUBMODULE SS4 FOR CS7 , SIMADYN D PROTOCOLL DUST 1,2,3,7
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643269703
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.432 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1681-0EK1 Siemens

$4,889.63

Only 2 units left

Control system SIMADYN D Interface module SE49.1, Synchronization module SA60

Siemens 6DD2920-0AR1 Siemens

$1,377.50

Only 3 units left

PLC Direct is not an authorized distributor. We offer a broad range of in-stock products with minimal lead time.

Siemens 6DD1600-0AE3 Siemens

$10,509.75

Only 6 units left

Product
Article Number (Market Facing Number)	6DD16000AE3
Product Description	SIMADYN D PM13 CPU-BOARD SETPOINT CASCADE L- AND C-BUS
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	Not available
Commodity Code	Not available
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	Not available
Group Code	R113
Country of origin	Not available
SCIP number	Not available
Delivery information
Net Weight (lb)	Not available
Package size unit of measure	Not available
Packaging Quantity	1

Siemens 6DD1660-0AH0 Siemens

$1,393.83

Only 3 units left

Buy the Siemens 6DD1660-0AH0 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD1660-0AH0 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD7090-0AA20 Siemens

$5,538.00

Only 7 units left

Buy the Siemens 6DD7090-0AA20 Communication Module - an industrial network interface providing controller-to-device connectivity. Supports standard industrial protocols for seamless automation integration. The Siemens 6DD7090-0AA20 is a direct replacement for existing communication installations.

Siemens 6DD1660-0AF0 Siemens

$1,325.25

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16600AF0
Product Description	SIMADYN D DIGITAL CONTR.SYSTEM SUBRACK INTERFACE BOARD CS3 SIMICRO MMC, LEBUS
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	Not available
Commodity Code	Not available
LKZ_FDB/ CatalogID	DA99E
Product Group	Not available
Group Code	P110
Country of origin	Not available
SCIP number	Not available
Delivery information
Net Weight (lb)	Not available
Package size unit of measure	Not available
Packaging Quantity	Not available

Siemens 6DD1610-0AE1 Siemens

$1,501.43

Only 3 units left

Buy the Siemens 6DD1610-0AE1 Control Board - an electronic circuit board providing essential control, signal processing, or interface functions for Siemens systems. This genuine Siemens 6DD1610-0AE1 PCB is a direct replacement for maintaining existing installations.

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PLC communication modules are plug-in hardware cards that extend a programmable logic controller's network connectivity, enabling data exchange with field devices, other controllers, SCADA systems, and enterprise networks via protocols such as PROFIBUS, PROFINET, EtherNet/IP, CC-Link, and Modbus. PLC Direct supplies PLC communication modules as an independent supplier, carrying surplus sealed, refurbished, and used hardware for maintenance and replacement in installed PLC systems.

Where Are PLC Communication Modules Used in Industrial Environments?

PLC communication modules are used wherever a controller must exchange data with field devices, distributed I/O, drives, HMIs, or higher-level systems over an industrial network protocol. These modules are installed in the PLC rack or backplane and handle all protocol-level communication independently of the CPU's primary scan cycle.

Facilities and operations that depend on PLC communication modules include:

Discrete manufacturing plants connecting PLC controllers to distributed I/O stations, servo drives, and robot interfaces over PROFIBUS or PROFINET.
Automotive assembly operations requiring high-speed, deterministic network communication across multi-PLC production line architectures.
Process industry facilities integrating PLCs with DCS systems, field instruments, and SCADA platforms over Modbus TCP or EtherNet/IP.
Water and wastewater treatment plants using communication modules to connect remote pump station controllers to centralized SCADA networks.
Food and beverage processing facilities coordinating PLC-to-PLC data exchange across filling, packaging, and conveyor control systems.

A failed or discontinued PLC communication module can isolate an entire controller from its network, making replacement availability a direct operational priority for maintenance teams.

Which Brands of PLC Communication Modules Does PLC Direct Stock?

PLC Direct stocks PLC communication modules across the major controller platforms and industrial network protocols deployed in installed automation systems worldwide.

Siemens SIMATIC CP343 and CP443 series: Communications processors for SIMATIC S7-300 (CP343-1) and S7-400 (CP443-1) controllers, covering Industrial Ethernet via TCP/IP, PROFINET IO, and S7 communication protocols.
Mitsubishi Electric MELSEC Q Series network modules: QJ71E71-100 Ethernet interface modules and QJ61BT11N CC-Link master/local modules for MELSEC Q Series systems, enabling Ethernet and CC-Link network connectivity within installed Q Series architectures.
Omron CJ Series communication modules: CJ1W-EIP21 EtherNet/IP communication modules for CJ Series PLC systems, supporting EtherNet/IP tag data link and message communication with compatible field devices and controllers.
ABB S500 communication interface modules: CI541-DP PROFIBUS and CI592-CS31 interface modules for AC500-based systems, extending distributed I/O connectivity across PROFIBUS DP and CS31 fieldbus networks.

PLC Direct carries PLC communication modules as surplus sealed, refurbished, and used hardware, giving maintenance teams options across condition grades and budget requirements.

What Should You Know Before Ordering PLC Communication Modules?

Hardware condition options: PLC Direct supplies PLC communication modules in surplus sealed, refurbished, and used conditions. Surplus sealed units are factory-sealed stock that has not been previously installed; refurbished modules have been inspected and tested to confirm operational functionality; used hardware is sourced from decommissioned systems and suits facilities managing lifecycle replacements under budget constraints.

Compatibility and part identification: PLC communication modules are platform-specific and must be matched to the correct controller series, rack slot type, and firmware environment. A CP343-1 for the S7-300, for example, is not compatible with an S7-400 rack. Confirm the full part number, controller series, and target protocol from the installed system's hardware documentation or network configuration before ordering.

Warranty: All PLC communication module hardware purchased from PLC Direct carries a standard 1-year PLC Direct warranty covering defects and functionality, applicable to surplus sealed, refurbished, and used products.

PLC Direct supplies PLC communication module hardware for replacement and maintenance purposes and does not provide system design, programming, or integration services.

Frequently Asked Questions

A PLC communication module handles network protocol processing independently of the controller CPU, managing data exchange with field devices, distributed I/O, drives, and higher-level systems over protocols such as PROFIBUS, PROFINET, EtherNet/IP, and CC-Link. By offloading network communication to a dedicated module, the CPU scan cycle is not interrupted by network traffic, maintaining deterministic control performance.

In most cases a like-for-like replacement of the same part number will restore network communication without changes to the controller program, as the module's protocol configuration is typically stored in the CPU project rather than in the module itself. However, some platforms require the module to be initialized or assigned a network address during commissioning, so the system's network configuration documentation should be reviewed before installation.

PROFIBUS is a serial fieldbus protocol operating over RS-485 physical layer at data rates up to 12 Mbps, widely installed in legacy automation systems from the 1990s onward. PROFINET runs over standard Industrial Ethernet infrastructure at 100 Mbps or higher and supports real-time and isochronous communication modes; it is the current standard for Siemens-based networks and increasingly predominant across other platforms. Modules for each protocol are not interchangeable even within the same controller family.

The most reliable method is to read the part number directly from the installed module's label and cross-reference it against the controller's hardware manual to confirm the rack slot type, protocol, and firmware compatibility. For Siemens S7-300 and S7-400 systems, the CP part number encodes both the protocol and the controller family it is designed for.

Many communication modules for legacy platforms including the Siemens SIMATIC S7-300 CP343 series and Mitsubishi MELSEC Q Series network modules remain available through independent suppliers even after manufacturer discontinuation, as installed base demand continues well beyond the end of production. Contact PLC Direct with the part number to check current availability.