To Next PageTo Next Page
Need help?Do you have a question about the Pilz PSS SB DI8O8 and is the answer not in the manual?
Describes the module's features like digital inputs, outputs, and power supplies.
Specifies the validity period and version of the PSS SB DI8O8 documentation.
Outlines the necessary CPU and system software versions for module configuration.
Details the 8 digital inputs, signal levels, and input filters for safety-related devices.
Explains signal detection timing, pulse suppression, and event telegrams for input signals.
Describes how input signal changes are processed, acknowledged, and reported.
Covers the 8 digital outputs, their switching types, current ratings, and dual-pole configurations.
Explains the use of test pulse outputs for verifying input device wiring and their load capacity.
The Pilz PSS SB DI8O8 is a decentralized input/output module designed for use with SafetyBUS p-compatible Programmable Safety Systems (PSS-Range). It serves as a crucial component for connecting safety-related input devices and controlling various outputs in industrial automation environments. The module is engineered to enhance safety and operational efficiency by providing reliable signal detection, output control, and diagnostic capabilities.
The PSS SB DI8O8 module integrates 8 digital inputs, 8 digital outputs, and 2 dedicated test pulse outputs. The inputs are versatile, supporting both single and dual-channel safety-related input devices, with or without test pulses. This flexibility allows for a wide range of safety applications, from basic to complex. The module's inputs and outputs are managed by a SafetyBUS p-compatible PSS master, ensuring synchronized and safe operation within the broader safety system.
The module's device address is configured via an address switch on the unit, allowing for unique identification within the SafetyBUS p network. Inputs can be organized into two I/O-groups, providing a structured approach to managing different safety functions.
The output section comprises 6 positive-switching and 2 negative-switching 2 A outputs. Two of the positive-switching outputs can be paired with two negative-switching outputs to form dual-pole outputs, offering enhanced control for specific applications. Individually, the negative-switching outputs are suitable for non-safety-related applications where switching to earth is permissible. All outputs are equipped with protection against short circuits, overloads, and excess temperatures, ensuring robust and reliable operation. They are compatible with both resistive and inductive loads, while positive-switching outputs can also handle capacitive loads up to 1 µF.
The PSS SB DI8O8 requires two 24 V supplies with a common earth: one "Supply" for the module electronics and test pulse outputs, and a separate "Load Supply" for the outputs. This separation enhances system resilience by isolating power domains. Galvanic isolation from SafetyBUS p is achieved through optocouplers, further improving signal integrity and safety.
The module's inputs are designed to detect "High" signals at 24 VDC (+15 ... +30 VDC) and "Low" signals at 0 VDC (-3 ... +5 VDC), with integrated input filters to ensure clean signal reception. Input status is continuously transmitted to the CPU on the PSS master via SafetyBUS p. Yellow LEDs provide immediate visual feedback on input status, lighting up when a "1" signal is present. Diagnostic circuitry actively monitors input functions, including the input filter. In the event of an error, all outputs in the affected I/O-group are switched off, and the I/O-group enters a STOP condition, with an error telegram stored on SafetyBUS p and in the module's error buffer.
For applications not utilizing test pulses, single-channel input devices can be used for safety categories up to 2 (EN 954-1), and dual-channel devices for categories up to 3. Proper wiring is essential to prevent short circuits in external wiring. For higher safety categories (above 2 for single-channel and above 3 for dual-channel), test pulses are mandatory.
Signal detection at inputs requires a signal to be present for a duration longer than the configured Event Timeout in the PSS WIN-PRO system software to trigger an Event Telegram. Signals shorter than 500 µs (pulse suppression time) are ignored to prevent spurious triggers. The module supports two signal change behaviors: "Default," where only the first signal change is registered, and "Fast," where all signal changes are stored in a FIFO telegram buffer and transmitted sequentially upon acknowledgment.
The outputs provide approximately 24 VDC for positive-switching outputs and 0 VDC for negative-switching outputs when a "1" signal is received from the PSS master. Green LEDs indicate output status. Diagnostic circuitry continuously tests output functions, comparing their status with the process image. Outputs are periodically switched on/off to verify transistor functionality and monitor for shorts between outputs. Outputs can be excluded from these tests through configuration if the plant is sensitive to fast switching, though this may affect fault detection time.
The two dedicated test pulse outputs (T0 and T1) are supplied from the module's main supply and are used for testing input device wiring. They are primarily for inputs operating on the zero signal principle for safety-related applications. Test pulses are allocated to inputs via the system software configurator, with each test pulse having a maximum load capacity of 0.5 A.
The module connects to SafetyBUS p via a male 9-pin D-Sub connector, supporting fibre-optic couplers. Device addresses (32-95) are set via the configurator. The module can be logically divided into Section A and Section B, which can belong to different I/O-Groups, allowing for flexible system design. Outputs always belong to Section A.
The PSS SB DI8O8 is designed for ease of installation and maintenance. It can be mounted on a 35 mm DIN-rail or screwed onto a mounting plate. Clear labelling strips for I/Os and LEDs for operating status, supply voltage, and I/O status facilitate quick visual checks and troubleshooting. The "Device" LED, a dual-colored indicator, provides comprehensive status information: red for device errors, flashing red for periphery errors, green for error-free operation, and off for system startup issues. The "SB active" LED indicates SafetyBUS p connection status, and the "I/O Group" LED shows the RUN/STOP status of configured I/O groups.
For commissioning, it is crucial to refer to the "PSS SB DI8O8 Installation Manual" and "SafetyBUS p System Manual." The module's functional earth requirements are automatically met when attached to an earthed DIN rail. A critical commissioning step involves simulating an error for every safety-related positive-switching output by generating a short circuit between the output and 24 V after the output is set to "1" by the user program. This ensures that the output test is effective and no outputs have been incorrectly excluded.
During recommissioning, a full function test is recommended, as terminal blocks are not designed for frequent exchange, and errors may occur during reinsertion. In case of a module defect or wiring error, all affected I/O group outputs switch off, and the I/O-group enters a STOP condition. An error telegram is stored on SafetyBUS p and in the module's error buffer, and an error message appears on the PSS master's display. The error stack display in the system software can be used to pinpoint the exact error location, aiding in efficient troubleshooting and maintenance.
General| Input Channels | 8 |
|---|---|
| Number of safe inputs | 8 |
| Output Channels | 8 |
| Number of safe outputs | 8 |
| Input Voltage | 24 V DC |
| Supply voltage | 24 V DC |
| Operating voltage | 24 V DC |
| Output type | Relay |
| SIL | SIL 3 |
| PL | PL e |
| Category | 4 |
| Safety category | 4 |
| Protection Class | IP20 |
| Connection type | Screw terminals |
| Product type | Safety Relay |
| Input voltage range | 19.2 V DC - 30 V DC |
| Weight | Approx. 300 g |
| Operating temperature range | -25°C to +55°C |
| Storage temperature range | -25°C to 70°C |
| Relative humidity | 95% non-condensing |
