PLC Communication Modules

Showing 769 - 792 of 878 products

$2,704.69

Only 5 units left

Product
Article Number (Market Facing Number)	6DD16820BC0 \| 6DD16820BC0
Product Description	* SPARE PART* SIMADYN D SUBRACK SR24.1 24V DC 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	662643270112
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)	38.140 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1681-0CB2 Siemens

$1,827.00

Only 7 units left

Buy the Siemens 6DD1681-0CB2 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD1681-0CB2 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1681-0AG2 Siemens

$1,937.20

Only 7 units left

Product
Article Number (Market Facing Number)	6DD16810AG2 \| 6DD16810AG2
Product Description	* spare part * SIMATIC TDC, binary output SB70 8 BO, DC/AC max. 120 V, LED display, galvanic isolation
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	Not available
UPC	662643035001
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)	1.027 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1642-0AB0 Siemens

$2,889.63

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 6DD1606-1AA0 Siemens

$6,021.43

Only 4 units left

Product
Article Number (Market Facing Number)	6DD16061AA0
Product Description	SIMADYN D PROCESSOR MODULE PT2 TECHNOLOGY
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	4315
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	1.345 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD3470-0AC0 Siemens

$601.76

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD34700AC0
Product Description	SIMADYN D STANDARD PLANNING AID 6RA24/6SE12 ACCURATE SYNCHRONISM SW20 W/O OPERATING INSTRUCTIONS FEASABLE WITH AND W/O 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	85049099
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4315
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.101 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1607-0CA1 Siemens

$10,100.19

In stock, 14 units

Product
Article Number (Market Facing Number)	6DD16070CA1 \| 6DD16070CA1
Product Description	* spare part * SIMATIC S7-400, EXM 438-1 I/O extension for FM 458 4x analog outputs 16-bit EXM 438-1 not spare part-compatible for EXM438
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	4019169120531
UPC	662643297928
Commodity Code	85389091
LKZ_FDB/ CatalogID	ST.DA99
Product Group	4100
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	2.273 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1610-0AH3 Siemens

$1,721.15

Only 3 units left

Product
Article Number (Market Facing Number)	6DD16100AH3 \| 6DD16100AH3
Product Description	SIMATIC TDC MC521 memory module 2 MB Flash-EPROM, 8 KB EEPROM
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	4025515739715
UPC	662643034806
Commodity Code	85235110
LKZ_FDB/ CatalogID	ST.DA99
Product Group	4476
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.104 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1842-0AA0 Siemens

$3,905.00

Only 7 units left

Product
Article Number (Market Facing Number)	6DD18420AA0 \| 6DD18420AA0
Product Description	*Spare part* SIMADYN D T400 with axle winder with min. documentation German/English without user manual T400-axle winder
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643035315
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)	1.025 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1681-0EB1 Siemens

$740.64

Only 3 units left

Product
Article Number (Market Facing Number)	6DD16810EB1
Product Description	SIMADYN D INTERFACE MODULE SE41.1 8BI, 48V, LED, GALVANIC ISOLATION
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)	0.364 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1681-0AH2 Siemens

$467.69

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16810AH2
Product Description	SIMADYN D INTERFACE MODULE SA10 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)	0.741 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1683-0BE0 Siemens

$10,621.67

Only 4 units left

Product
Article Number (Market Facing Number)	6DD16830BE0 \| 6DD16830BE0
Product Description	* SPARE PART* SIMADYN D POWER SUPPLY UNIT SP9 5V/40A, 15V, 24V DC INPUT
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643270167
Commodity Code	85044090
LKZ_FDB/ CatalogID	ST9.DA99T
Product Group	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	22.708 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD3440-0AB0 Siemens

$2,288.10

Only 5 units left

Buy the Siemens 6DD3440-0AB0 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD3440-0AB0 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1684-0GH0 Siemens

$0.00

Sold Out

Product
Article Number (Market Facing Number)	6DD16840GH0 \| 6DD16840GH0
Product Description	SIMATIC TDC Service cable SC67 for connection to the CPU service interface 10-pole shielded, Length 7m
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	4025515739883
UPC	662643297379
Commodity Code	85444290
LKZ_FDB/ CatalogID	ST.DA99
Product Group	4476
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.454 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD3440-0AB2 Siemens

$434.99

Only 3 units left

Buy the Siemens 6DD3440-0AB2 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD3440-0AB2 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1610-0AH6 Siemens

$0.00

Sold Out

Product
Article Number (Market Facing Number)	6DD16100AH6 \| 6DD16100AH6
Product Description	SIMATIC TDC MC510 memory module 8 MB Flash-EPROM, 8 KB EEPROM
Product family	Not available
Product Lifecycle (PLM)	PM410:Product cancellation
Additional Product Information
EAN	4025515739739
UPC	662643297348
Commodity Code	85235110
LKZ_FDB/ CatalogID	ST.DA99
Product Group	4476
Group Code	R132
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.104 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1610-0AG5 Siemens

$0.00

Sold Out

Product
Article Number (Market Facing Number)	6DD16100AG5 \| 6DD16100AG5
Product Description	* SPARE PART* SIMADYN D MEMORY SUBMODULE MS45 16 BIT,512KB RAM,8KB EEPROM
Product family	Not available
Product Lifecycle (PLM)	PM500:Discontinued Product or end of PLM & Support
Additional Product Information
EAN	Not available
UPC	662643265149
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)	0.143 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1681-0FA0 Siemens

$320.00

Only 3 units left

Buy the Siemens 6DD1681-0FA0 Communication Module - an industrial network interface providing controller-to-device connectivity. Supports standard industrial protocols for seamless automation integration. The Siemens 6DD1681-0FA0 is a direct replacement for existing communication installations.

Siemens 6DD7092-0AA30 Siemens

$0.00

Sold Out

Buy the Siemens 6DD7092-0AA30 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD7092-0AA30 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1682-0BE0 Siemens

$11,202.30

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16820BE0
Product Description	* SPARE PART* SIMADYN D SUBRACK SR24.2 24V DCNATURAL CONVECTION 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	662643850888
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)	35.715 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1688-0AE1 Siemens

$456.00

Only 4 units left

Product
Article Number (Market Facing Number)	6DD16880AE1
Product Description	SIMADYN D COMMUNICATION SUBMODULE SS51 FOR CS7 , MASTER INTERFACE FOR BUS SYSTEM SINEC L2 DP
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	4230
Group Code	R111
Country of origin	Germany
SCIP number	Not available
Delivery information
Net Weight (lb)	0.417 lb
Package size unit of measure	Inch
Packaging Quantity	1

Siemens 6DD1682-0AB1 Siemens

$2,175.00

Only 1 unit left

Product
Article Number (Market Facing Number)	6DD16820AB1
Product Description	SIMADYN D DIGITAL CONTR.SYSTEM SUBRACK SR1 24PS,W/O POWER SUPPLY UNIT/FAN
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	DA99
Product Group	Not available
Group Code	P121
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 6DD1610-0AH2 Siemens

$1,327.68

Only 5 units left

Buy the Siemens 6DD1610-0AH2 - a genuine Siemens industrial automation component engineered for reliable performance in demanding manufacturing and process control environments. The Siemens 6DD1610-0AH2 is a direct drop-in replacement for existing installations and ships ready for integration.

Siemens 6DD1681-0BD1 Siemens

$382.56

Only 3 units left

Buy the Siemens 6DD1681-0BD1 I/O Module - an industrial input/output module providing signal interfacing for Siemens automation systems. Features reliable signal conditioning, industrial-grade isolation, and seamless Siemens platform integration. The Siemens 6DD1681-0BD1 is a direct replacement for existing I/O 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.