How to Select an Interface Relay for PLC Outputs
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- Part number
- 6ES7241-1CA50-0XB0
- Model no
- CB 1241 RS 485
In stock · 50+
Dispatch
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· From Türkiye
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SIMATIC S7-1200Siemens 6ES7241-1CA50-0XB0 SIMATIC S7-1200 CB 1241 RS485 Communication Board
SIMATIC S7-1200 CB 1241 communication board, RS485, Modbus RTU and USS support.
Description
About the CB 1241 RS 485
About the CB 1241 RS 485
The Siemens 6ES7241-1CA50-0XB0 SIMATIC S7-1200 CB 1241 is a communication board that adds one RS 485 interface to a compact CPU, supporting Freeport, ASCII, Modbus RTU master/device, and USS protocols at up to 250 kbit/s. It draws 75 mA from the backplane bus and connects over point-to-point cable runs up to 1000 m.
Certifications & Standards
- CE
- UL
- cULus
- RCM
- KC
Selection Notes
The CB 1241 plugs into the S7-1200 CPU's onboard communication board slot rather than a rack expansion position, adding RS 485 connectivity without using up a signal-module slot. In Modbus RTU master mode the CPU can poll up to 247 slave devices under standard Modbus addressing, with a maximum of 32 devices per physical segment before a repeater is required; Modbus RTU device mode instead lets another master poll this CPU. The USS protocol, available as a library function, is the relevant mode when the RS 485 link talks to Siemens drives rather than third-party Modbus instruments.
Applications
Adds RS 485 serial connectivity to an S7-1200 for Modbus RTU instrument networks, USS-based drive control loops, or Freeport ASCII communication with third-party serial devices.
Specification
Full specification
General information 1
| Product type designation | CB 1241 RS 485 |
|---|
Input current 1
| from backplane bus 5 V DC, typ. | 75 mA |
|---|
Power loss 1
| Power loss, typ. | 0.4 W |
|---|
Show all 71 specifications ↓ Show less ↑68 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 8 27-24-22-08, Logistics.
Identification 10
| Part number | 6ES7241-1CA50-0XB0 |
|---|---|
| Type designation | CB 1241 RS 485 |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4034106036195 |
| ETIM class | EC001423 |
| eCl@ss | 27242208 |
Interfaces 8
| Interfaces/bus type | RS 485 |
|---|---|
| Number of interfaces | 1 |
| Point-to-point connection: Cable length, max. Integrated protocol driver | 1 000 m |
| 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 1
| 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 | 15 mm |
|---|---|
| Height | 62 mm |
| Depth | 63 mm |
Weights 1
| Weight, approx. | 29 g |
|---|
EClass 8 27-24-22-08 4
| eClass | 7.1 27-24-22-08 |
|---|---|
| ETIM | 10 EC001423 |
| IDEA | 4 3564 |
| UNSPSC | 15 32-15-17-05 |
Logistics 7
| Net weight | 0.043 kg |
|---|---|
| Package dimensions | 83 × 36 × 80 mm |
| Country of origin | DE |
| Shipping weight | 0.543 kg |
| Ships from | Türkiye |
| Dispatch | 12 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 01 Nov 2026
Documents
Documents for 6ES7241-1CA50-0XB0
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 CB 1241 RS 485
What is the HS code of CB 1241 RS 485 for customs?
The tariff (HS) code on file for CB 1241 RS 485 is 85176200.
What is the EAN of CB 1241 RS 485?
The EAN (GTIN) of CB 1241 RS 485 is 4034106036195.
Where does CB 1241 RS 485 ship from, and how fast?
CB 1241 RS 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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Customer reviews
Series
Siemens SIMATIC S7-1200
- Brand
- Siemens
- Series
- SIMATIC S7-1200
