Delta AH500 PLC system operation and maintenance

After connecting the CPU via USB or Ethernet, click "Download" in HWCONFIG to write the hardware configuration and parameters to the PLC.

If the actual hardware does not match the configuration, the BUS FAULT LED of the CPU will light up. The "I/O Scan" function can automatically read the actual module configuration and update the project.

Network communication configuration: PLC Link and Ether Link

AH500 supports data exchange between multiple PLCs through RS-485 (PLC Link) and Ethernet (Ether Link).

5.1 PLC Link (RS-485 master-slave communication)

There is only one master station in a network, with a maximum of 32 slave stations.

The master station periodically reads/writes to slave devices (M, D, L, etc.).

Open NWCONFIG in ISPSoft, add RS-485 network, drag the node into the network, and set the station address.

Double click on the network to enter the PLC Link editor: select the main station port, set communication parameters (baud rate, data format), create a data exchange table - each record contains the slave station address, read/write direction, main station starting address, slave station starting address, and data length.

After downloading, the exchange status can be viewed in real-time through "Monitoring and Download". Each slave station corresponds to a status icon, with green indicating normal and red flashing indicating error.

Common errors:

Error codes 16 # 9A01~9A20: Incorrect data exchange settings at the slave station (such as device type or address out of range).

16 # 9A21~9A40: Communication failure between master and slave - check cable wiring and baud rate consistency.

16 # 9A41~9A60: No response from the substation - check if the substation power supply is normal.

5.2 Ether Link (Ethernet Data Exchange)

Based on TCP/IP, there is no master-slave concept, and each node can request data from other nodes.

Up to 128 data blocks, with a maximum of 1900 words per block.

Create an Ethernet network in NWCONFIG and assign IP addresses to each node (consistent with the IP set in HWCONFIG).

In the Ether Link configuration table, add a read entry for each demand node: select remote node, remote starting device, local storage device, and data length.

Startup mode options: always running, always stopping, or controlled by special auxiliary relays (SM1770, etc.).

Common errors:

16 # 6300: An unsupported device was used in Ether Link (only available for M, D, L).

16 # 6301: The device address is out of range.

16 # 6303: Remote device terminates connection - check network physical connection and firewall settings.

Common troubleshooting: LED indicator lights and error codes

6.1 Meaning of CPU module LED indicator lights

Meaning of LED status

RUN green constant light user program is executing

Green flashing PLC in STOP state

Extinguish PLC malfunction, no program, or invalid program

ERROR is a serious error (such as program damage, parameter errors, memory exceptions) with a constant red light

Red flashing minor errors (such as scan timeout, program syntax error, communication settings error)

Extinguish normally

BUS FAULT red constant light I/O bus serious error (module configuration mismatch, access error)

Red flashing I/O bus minor error (abnormal module)

Extinguish normally

SYSTEM flashing CPU reset, device value clearing, or SD card backup/restore in progress

6.2 Common reasons and solutions for the constant brightness of ERROR LED

Error code description and solution

16 # 000B program is damaged and needs to be re downloaded

16 # 000D CPU parameter damage, reset parameters and download again

16 # 0011 PLC ID Error Check if the PLC ID matches the project (SM9)

16 # 0012 Password Error: Enter the correct password or clear the password (power off reset required)

16 # 0015 module table incorrect use HWCONFIG I/O scan to correct configuration

16 # 0050~005A Lock Device Area Memory Exception Reset CPU and Download Again (SM9)

6.3 Common causes and solutions for ERROR LED flashing

Error code description and solution

16 # 000A scan timeout (watchdog) Increase watchdog setting or optimize program to shorten scan cycle

The program downloaded at 16 # 000C is incorrect. Please recompile the program before downloading again

16 # 0033~0035 COM1 communication setting error HWCONFIG reset COM parameters and download

16 # 2003 program checks whether the array and index register exceed the limit when the device is out of range

16 # 200B instruction constant out of range. Modify the constant value in the program

16 # 2012 Division Operation Error (Dividing by 0) Modify the program to avoid division by zero

16 # 6001 IP Address Illegal Reset Ethernet IP

16 # 6500 Data Exchange Initialization Failure Check if Modbus TCP or Ether Link configuration quantity exceeds limit

6.4 BUS FAULT LED Exception Handling

BUS FAULT is always on: usually corresponding to the ERROR LED of a certain I/O module. Check if the module is powered on and if it is damaged. Use HWCONFIG online diagnostics to view specific error codes (16 # 1401-16 # 140D). For example, 16 # 1402 indicates that the actual module arrangement is inconsistent with the module table.

BUS FAULT flashing: A module has a slight error (such as analog input exceeding limit, communication quality degradation).