How to Select an Interface Relay for PLC Outputs
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- Part number
- 6ES7921-5CB20-0AA0
- Model no
- Fully modular connection
SIMATIC TOP connectSiemens 6ES7921-5CB20-0AA0 SIMATIC TOP connect Front Connector S7-1500 32 I/O 50-Pole PLC Connection Module
Siemens 6ES7921-5CB20-0AA0 front connector module, 1x50-pole IDC, screw terminals, for S7-1500 digital 32 I/O modules.
Description
About the Fully modular connection
About the Fully modular connection
The Siemens 6ES7921-5CB20-0AA0 is a SIMATIC TOP connect front connector module for digital 32-channel I/O modules on the S7-1500. It carries a single 50-pole IDC connector for the field cabling and feeds potential supply through 4 screw terminals, rated 24 V DC at up to 1 A per plug-in contact.
Certifications & Standards
- cULus
Selection Notes
A single 50-pole IDC connector replaces the four 16-pole connectors used on the 6ES7921-5AB20-0AA0 for the same 32-channel digital I/O card, so this variant suits a one-cable connection to the terminal module instead of four separate cables. The 4 screw terminals are wired L+ only (no M return on this connector), sized for 0.5-2.5 mm² stranded conductor. Choose the 4x16-pole version instead when the downstream terminal module or existing cabling is built around four IDC cables rather than one 50-pole run.
Specification
Full specification
General 5
| target system | SIMATIC S7-1500 |
|---|---|
| suitability for use | Digital I/O modules |
| product brand name | SIMATIC Top connect |
| product type designation | Fully modular connection |
| product designation | Front connector module |
Electrical data / header 4
| operating voltage / at DC: rated value | 24 V |
|---|---|
| operating voltage / at DC: maximum | 60 V |
| continuous current / at DC / per plug-in contact / maximum | 1 A |
| total current / maximum | 2 A; for mounting position horizontal |
Connection method 21
| number of poles | 40; of the front connector |
|---|---|
| Product component / with shield | No |
| type of electrical connection / for connecting cable | Plug-in connection |
| number of poles / at the 1st interface | 50; the IDC connector for the connection cable |
| number of the plug contacts / of the electrical connection | 1 |
| wire length / maximum | 30 m; between front connector module and terminal module |
| number of terminals | 4; 4 x 1 x L+ |
| type of electrical connection / for power supply | Screw-type terminal |
| position / of the terminal | at the top |
| type of connectable conductor cross-sections / solid | No |
| connectable conductor cross-section: for flexible conductor / with core end processing | 0.25 ... 1.5 mm2; End sleeve according to DIN 46228/1 or DIN 46228/4 with plastic collar max. 0.75 mm2 |
| connectable conductor cross-section: stranded | 0.5 ... 2.5 mm2 |
| connectable conductor cross-section: finely stranded / without core end processing | 0.5 ... 2.5 mm2 |
| connectable conductor cross-section: finely stranded / with core end processing | 0.25 ... 1.5 mm2 |
| type of wire end sleeve: with plastic sleeve / according to DIN 46228-4 | Length 10mm |
| type of wire end sleeve: without plastic sleeve / according to DIN 46228-1 | Length 10mm |
| number of cables / per connection | 2; Connection for internal system: Combination of 1 or 2 Wires until the sum total of cross sections be achieved in a ferrule. |
| stripped length | 10 mm |
| outer diameter / of the wire insulation | 3.1 mm; to the connection of the supply terminal |
| width of screwdriver blade | 3.5 mm |
| tightening torque / with screw-type terminals | 0.4 ... 0.7 N·m |
Show all 61 specifications ↓ Show less ↑31 more values in Identification, Standards, specifications, approvals, Ambient conditions, Mechanical data, Additional information, Logistics.
Identification 10
| Part number | 6ES7921-5CB20-0AA0 |
|---|---|
| Type designation | Fully modular connection |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4047623602477 |
| ETIM class | EC001284 |
| eCl@ss | 27141106 |
Standards, specifications, approvals 4
| certificate of suitability / cULus approval | Yes |
|---|---|
| design tested acc. to type of protection / EEx e | No |
| overvoltage category | 2 |
| degree of pollution | 2 |
Ambient conditions 3
| operating temperature | 0 ... 60 °C |
|---|---|
| ambient temperature: during operation | 0 ... 60 °C |
| ambient temperature: during storage | -40 ... +70 |
Mechanical data 5
| mounting type | direct mounting |
|---|---|
| color / of the enclosure | black |
| product feature / transparent | No |
| material / of the insulating body | other |
| product component / required / end cover plate | No |
Additional information 3
| manufacturer's article number / of device connector / usable | replacement for S7-1500 40 pole |
|---|---|
| other information | technical specifications apply to rated input voltage values and +25 °C ambient temperature (if not otherwise specified) |
| marketing text | The front connector module for SIMATIC S7-1500 with screw terminals for potential feed to connect 50-pole cables represents a modified front connector for connection to a digital I/O module. This is plugged into the module to be wired instead of the front connector. Here the cables are plugged in and connected to the connection module.This modified front connector module is part of the fully modular connection of SIMATIC TOP connect for the fastest and safest system cabling. In addition to low wiring costs, error sources in cabling can be significantly reduced. Sensors and actuators from the peripherals are attached to the connection modules of SIMATIC TOP connect and linked to the SIMATIC S7-300 via connecting cable and front plug-in module. |
Logistics 6
| Net weight | 0.085 kg |
|---|---|
| Country of origin | Romania |
| Shipping weight | 0.585 kg |
| Ships from | Türkiye |
| Dispatch | — |
| Stock | On request |
Source: manufacturer data · Last verified: 01 Nov 2026
Documents
Documents for 6ES7921-5CB20-0AA0
No documents are on file for this part yet.
Ask us for the datasheet
Certifications
Certifications and standards
- / cULus approval
Quick answers
Questions about the Fully modular connection
What is the rated current of Fully modular connection?
The rated current of Fully modular connection is 1 A.
Which supply voltage is Fully modular connection rated for?
The rated operational voltage of Fully modular connection is 24 V DC.
What is the HS code of Fully modular connection for customs?
The tariff (HS) code on file for Fully modular connection is 85366990.
What is the EAN of Fully modular connection?
The EAN (GTIN) of Fully modular connection is 4047623602477.
Where does Fully modular connection ship from, and how fast?
Fully modular connection ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival.
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