SCHNEIDER PowerPact ™ H. Modbus Communication User Guide for J and L-type Circuit Breakers

Protection parameters (8754-8930): covering protection parameters such as long delay, short delay, instantaneous, ground fault, locked rotor, imbalance, underload, long start, neutral line, etc., supporting the configuration of key parameters such as protection threshold and delay time through dedicated commands.

Log Register (5732-29549): Contains 10 alarm logs, 17 trip logs, and 10 maintenance operation logs, each with a timestamp (ULP DATE format), supporting fault tracing and maintenance record queries.

② BSCM module register

Identification register (551-557): Product identification (15149 corresponds to BSCM module), serial number (PPYYWWDnnn format), supports module identity recognition and traceability.

Status registers (563-564): Circuit breaker status (OF input, SD input, SDE input status), communication electric mechanism status (electric mechanism availability, manual/automatic mode, previous command execution status, etc.), real-time monitoring of circuit breaker operation status.

Maintenance indicator (571-582): includes 7 counters including cumulative OF counter (non resettable), OF counter, SD counter, SDE counter, and on/off command counter. It supports setting a threshold (default 5000) and generates an alarm when the counter reaches the threshold to assist in the development of maintenance plans.

Event log (602-652): 10 event records, including event identification, date and time, event status, supporting event tracing, event identification covering SD contact changes, threshold triggering, internal faults, and other scenarios.

③ IO module register

Analog input (13824-13929/16824-16929): Supports Pt100 temperature sensor input, measurement range -50~250 ℃, updated once per second, including data quality identification (valid/invalid) and data change timestamp.

Digital input/output (13930-14000/16930-17000): 6 digital inputs, 3 digital outputs, supporting status monitoring and control. The digital input status includes an "on/off" indicator, and the digital output supports remote control.

Alarm status (203-205): User defined alarm (201-210) activation status, supports custom alarm thresholds and triggering conditions, and the corresponding bit identifier when the alarm is activated is 1.

Hardware settings (197-198): including module hardware configuration parameters, supporting the adaptation configuration of IO modules and circuit breakers.

Remote Command and Control Process

(1) Command execution general process

Load command parameters into the buffer (registers 8000-8015), specifying the command code, parameter length, destination, security type, password, and additional parameters.

Send command requests through Modbus function code 0x10 (write multiple registers) to ensure that the parameter format is consistent with the register requirements.

Read the command status register 8021. If the content is 0x0003, it indicates that the command is being executed and needs to wait continuously.

Read the command code register 8020 and confirm that it matches the command code input in step 2. If it does not match, execute the process again.

Read the error code of the least significant bit of register 8021, where 0 indicates successful execution and non-zero indicates troubleshooting based on the error code (such as password errors, insufficient permissions, etc.).

(2) Example of Key Commands

Circuit breaker opening (command code 904)

Permission requirement: Administrator/operator level password.

Execution steps: ① The padlock is in the open state; ② Write command code 904 to register 8000, with a parameter length of 10 bytes, destination 4353 (0x1101), security type 1, and enter the administrator/operator password; ③ Confirm the command execution status according to the general process; ④ Verify the status register of the circuit breaker (32001) and confirm successful disconnection.

Protection parameter configuration (taking long delay protection as an example, command code 45192)

Permission requirement: Administrator level password.

Execution steps: ① Write command code 45192 to register 8000, with a parameter length of 18 bytes and destination 5121 (0x1401); ② Configure parameters such as Ir setting value (determined by the rated current In of the transformer), TR delay (500-16000ms for distribution applications), motor category (5-30 seconds for motor applications), etc; ③ Execute and verify the configuration results according to the general process, and read the configured parameters through registers 8754-8763.

Data synchronization command (set date and time, function code 0x2B, sub function 0x10)

Permission requirement: No password protection, can still be executed when the padlock is closed.

Execution steps: ① The main device sends a command containing the target date and time (year, month, day, hour, minute, second, millisecond); ② Support broadcast mode (from device address 0) to synchronize all slave device times; ③ After a power outage, devices without batteries need to resynchronize their time. It is recommended to synchronize every 15 minutes to offset clock drift.

(3) Permission and Security Control

User permission classification: divided into four levels: Administrator (highest permission), Services, Engineer, and Operator. Different commands require corresponding permission passwords, such as protecting parameter configuration requires administrator passwords, and opening and closing commands require administrator/operator passwords.