How to Select an Interface Relay for PLC Outputs
A step-by-step guide to matching PLC output type, coil voltage and current, contact rating, and socket style when selecting an interface relay.
- Part number
- 6ES7241-1EA50-0XB0
- Model no
- CM 1241 RS 232 / 422 / 485
In stock · 49
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· From Türkiye
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SIMATIC S7-1200Siemens 6ES7241-1EA50-0XB0 SIMATIC S7-1200 CM 1241 RS232/422/485 Communication Module
CM 1241 communication module, RS232/422/485, Modbus RTU, USS, for SIMATIC S7-1200.
Description
About the CM 1241 RS 232 / 422 / 485
About the CM 1241 RS 232 / 422 / 485
The Siemens CM 1241 (6ES7241-1EA50-0XB0) is a SIMATIC S7-1200 communication module with one switchable RS232/RS422/RS485 interface, supporting Freeport, ASCII, Modbus RTU master and slave, and USS protocols. It connects the S7-1200 to serial field devices such as VFDs, meters, and third-party PLCs over up to 1,000 m on RS422/485, at transmission rates up to 250 kbit/s on RS485 and 115.2 kbit/s on RS232.
Certifications & Standards
- CE
- UL
- cULus
- RCM
- KC
Selection Notes
The single switchable RS232/422/485 port lets one module serve either a short point-to-point RS232 link or a 1,000 m multidrop RS422/485 segment, covering both a nearby HMI or printer connection and a longer Modbus RTU field bus without ordering two different modules. Choose the Modbus RTU master function when the S7-1200 needs to poll VFDs or meters directly; the built-in USS driver is the alternative when the field devices are Siemens drives instead of generic Modbus slaves.
Applications
Fits S7-1200 stations that need to talk to serial VFDs, energy meters, barcode scanners, or legacy RS232/485 equipment alongside the CPU's onboard PROFINET port.
Specification
Full specification
General information 1
| Product type designation | CM 1241 RS 232 / 422 / 485 |
|---|
Input current 1
| from backplane bus 5 V DC, typ. | 170 mA |
|---|
Power loss 1
| Power loss, typ. | 0.9 W |
|---|
Show all 72 specifications ↓ Show less ↑69 more values in Identification, Interfaces, Interface types, Protocols, Interrupts/diagnostics/status information, Degree and class of protection, Standards, approvals, certificates, Ambient conditions, Mechanics/material, Dimensions, Weights, EClass 9.1 27-24-22-08, Logistics.
Identification 10
| Part number | 6ES7241-1EA50-0XB0 |
|---|---|
| Type designation | CM 1241 RS 232 / 422 / 485 |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4034106035709 |
| ETIM class | EC001423 |
| eCl@ss | 27242208 |
Interfaces 8
| Interfaces/bus type | RS 232 (full duplex) / 422 / 485 |
|---|---|
| Number of interfaces | 1 |
| Point-to-point connection: Cable length, max. Integrated protocol driver | 1 000 m; RS 232 10 m shielded max., RS 422/485 1 000 m shielded max. |
| Point-to-point connection: Freeport | Yes |
| Point-to-point connection: ASCII | Yes; Available as library function |
| Point-to-point connection: Modbus RTU master | Yes |
| Point-to-point connection: Modbus RTU device | Yes |
| Point-to-point connection: USS | Yes; Available as library function |
Interface types 2
| RS 232: Transmission rate, max. | 115.2 kbit/s |
|---|---|
| RS 485: Transmission rate, max. | 250 kbit/s |
Protocols 6
| Integrated protocols Freeport: Telegram length, max. | 4 kbyte |
|---|---|
| Integrated protocols Freeport: Bits per character | 7 or 8 |
| Integrated protocols Freeport: Number of stop bits | 1 (Standard), 2 |
| Integrated protocols Freeport: Parity Modbus RTU master | no parity (standard); even, odd, mark (parity bit always 1); space (parity bit always 0) |
| Integrated protocols Freeport: Address area | 1 through 65535 (Standard Modbus addressing) |
| Integrated protocols Freeport: max. number of devices Modbus RTU device | 247; slave numbers 1 through 247, per MODBUS network segment maximum 32 devices, additional repeaters needed to expand the network to maximum configuration |
Interrupts/diagnostics/status information 3
| Diagnostics function | Yes |
|---|---|
| Diagnostics indication LED: DIAG LED | Yes |
| Diagnostics indication LED: for status of the outputs | Yes |
Degree and class of protection 1
| IP degree of protection | IP20 |
|---|
Standards, approvals, certificates 8
| CE mark | Yes |
|---|---|
| CSA approval | No |
| UL approval | Yes |
| cULus | Yes |
| FM approval | No |
| RCM (formerly C-TICK) | Yes |
| KC approval | Yes |
| Marine approval | No |
Ambient conditions 15
| Free fall: Fall height, max. | 0.3 m; five times, in product package |
|---|---|
| Ambient temperature during operation: horizontal installation, min. | -20 °C |
| Ambient temperature during operation: vertical installation, min. | -20 °C |
| Ambient temperature during storage/transportation: min. | -40 °C |
| Ambient temperature during storage/transportation: max. | 70 °C |
| Air pressure acc. to IEC 60068-2-13: Operation, min. | 540 hPa |
| Air pressure acc. to IEC 60068-2-13: Operation, max. | 1 140 hPa |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, min. | 540 hPa |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, max. | 1 140 hPa |
| Altitude during operation relating to sea level: Installation altitude, min. | -1 000 m |
| Relative humidity: Operation, max. | 95 %; no condensation |
| Vibrations: Vibration resistance during operation acc. to IEC 60068-2-6 | 3.5 mm from 5 - 8.4 Hz, 1g from 8.4 - 150 Hz |
| Vibrations: Operation, tested according to IEC 60068-2-6 | Yes |
| Shock testing: tested according to IEC 60068-2-27 | Yes; IEC 68, Part 2-27 half-sine: strength of the shock 15 g (peak value), duration 11 ms |
| Pollutant concentrations: SO2 at RH < 60% without condensation | S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60 % condensation-free |
Mechanics/material 1
| Enclosure material (front): Plastic | Yes |
|---|
Dimensions 3
| Width | 30 mm |
|---|---|
| Height | 125 mm |
| Depth | 100 mm |
Weights 1
| Weight, approx. | 178 g |
|---|
EClass 9.1 27-24-22-08 4
| eClass | 9 27-24-22-08 |
|---|---|
| ETIM | 10 EC001423 |
| IDEA | 4 3564 |
| UNSPSC | 15 32-15-17-05 |
Logistics 7
| Net weight | 0.178 kg |
|---|---|
| Package dimensions | 152 × 50 × 110 mm |
| Country of origin | CN |
| Shipping weight | 0.678 kg |
| Ships from | Türkiye |
| Dispatch | 12 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 01 Nov 2026
Documents
Documents for 6ES7241-1EA50-0XB0
No documents are on file for this part yet.
Ask us for the datasheet
Certifications
Certifications and standards
- CE mark
- UL approval
- cULus
- RCM (formerly C-TICK)
- KC approval
Quick answers
Questions about the CM 1241 RS 232 / 422 / 485
What is the HS code of CM 1241 RS 232 / 422 / 485 for customs?
The tariff (HS) code on file for CM 1241 RS 232 / 422 / 485 is 85176200.
What is the EAN of CM 1241 RS 232 / 422 / 485?
The EAN (GTIN) of CM 1241 RS 232 / 422 / 485 is 4034106035709.
Where does CM 1241 RS 232 / 422 / 485 ship from, and how fast?
CM 1241 RS 232 / 422 / 485 ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
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Reviews
Customer reviews
Series
Siemens SIMATIC S7-1200
- Brand
- Siemens
- Series
- SIMATIC S7-1200
