HIMA H41q/H51q Safety PLC System

Intrinsic Safety (Ex) i Module: Available in two models with PCB coating and without coating, suitable for hazardous areas. When using a coated Ex i module, the adjacent slot on the right must be kept empty or a blind plate with an isolation plate must be installed to ensure safe isolation.

4.2 Safe output module

All safety related output modules meet the AK 6 level requirements, and their key designs include:

Triple redundant shutdown: Three series connected semiconductor switches are used internally, far exceeding the requirement of two independent components for safe shutdown, achieving "integrated safe shutdown". Once the module fails, it will automatically switch to a safe power-off state.

Parallel capability: To improve availability, the output terminals of the safety type output module can be used in parallel without the need for external diodes.

L-Power supply design: When the negative terminal L of the power supply is cut off, there will be no voltage at the output terminal, so there is no need to wire L - as a ring feeder, simplifying the design and troubleshooting.

4.3 Safety shutdown mechanism

The core safety mechanism of HIMA PES is to drive the process to a safe state when a fault occurs. The system performs different levels of shutdown based on the location and severity of the fault:

Module shutdown: A testable output module with integrated safety shutdown function will automatically switch to a safe power-off state when an internal fault is detected.

Group shutdown: Up to 10 testable output modules can be defined as a group through the H8-STA-3 function block in the user program. When any module in the group fails, the user program can trigger the shutdown of the whole group.

Watchdog shutdown: In the event of an I/O bus failure, dual output module failure, or central module failure, the associated central module will cut off its watchdog signal (WD), resulting in the safe shutdown of all related output modules.

Power Supply and Distribution

5.1 System Voltage

The HIMA system uses two voltage levels: 24 V DC (L+/L -) for peripheral devices and 5 V DC for microprocessor systems. 5 V DC is generated by 24 V DC through a high-frequency switching power module (F7126 for H51q, F7130A for H41q).

5.2 Power Redundancy and Monitoring

Redundant configuration: In high availability (H/HR/HS/HRS) systems, multiple parallel power modules are equipped. When one module fails, other modules can seamlessly take over to ensure the continuous operation of the system.

Voltage monitoring: The 5V DC output voltage is monitored for undervoltage and faults by the central module or monitoring module (F7131). Fault information is transmitted to the user program through system variables for easy diagnosis.

Battery buffering: The sRAM and hardware clock on the central module are buffered by onboard lithium batteries. The sRAM of the coprocessor module (F8621A) in the H51q system is buffered by the lithium battery on the monitoring module F7131.

Communication Interface and Expansion

HIMA PES provides multiple communication interfaces to meet different levels of system integration requirements.

RS-485 interface: Each central module comes standard with 2 electrically isolated RS-485 interfaces, used to connect programmers (via H7505 converter) or build control system buses (HIBUS), with a maximum transmission rate of 57600 bps. In the H51q system, up to 6 additional RS-485 interfaces can be extended through up to 3 coprocessor modules (F8621A).

Ethernet interface: Through the communication module F8625, Ethernet communication that complies with the IEEE 802.3 10BaseT standard can be achieved, and up to 10 interfaces can be expanded.

Profibus DP interface: Through the communication module F8626, Profibus DP slave communication can be achieved, with a maximum transmission rate of 12 Mbit/s and the ability to expand up to 10 interfaces.

Installation, Maintenance, and Standardization

7.1 ESD Protection

The manual begins with the phrase 'Attention' emphasizing the crucial importance of electrostatic discharge protection. When performing maintenance on power, signal, and data lines, qualified personnel must operate and take all necessary ESD protection measures. Maintenance personnel must release their own static electricity before directly contacting these lines.

7.2 Module insertion and removal

I/O module: can be plugged and unplugged with power. When pulling out, first loosen the fixing screw and pull out the cable plug together. When inserting, first insert and secure the module, then insert the cable plug.

Central module: Before unplugging, remove the data cable and use the ejection lever on the module to separate it from the bus board. Before insertion, check the switch and jumper settings.

7.3 Grounding and Electromagnetic Compatibility

To meet CE requirements and ensure electromagnetic compatibility, strict grounding and shielding measures must be taken:

Grounding: The system supports floating or L-grounding operation. The grounding resistance should be ≤ 2 ohms. L - can only be grounded at one point within the system.

Shielding: The shielding layer of the communication data line must be grounded at the single end of the bus user side (such as H41q/H51q). On site cables (sensors/actuators) should use shielded cables and be laid separately from power cables.