Introduction
All Maple Systems HMIs programmed with EBPro (EasyBuilder Pro), including every cMT X Series and cMT Series model, are compatible with Modbus ASCII. Configure your Controller and HMI/cMT with the following parameters to establish reliable communication.
Supported Series: MODBUS ASCII CONTROLLER
HMI Settings
| Parameters | Recommended | Options |
|---|---|---|
| PLC type | MODBUS ASCII | |
| PLC I/F | RS485 | RS232/RS485 |
| Baud rate | 9600 | 9600/19200/38400/57600/115200 |
| Data bits | 8 | 7, 8 |
| Parity | Even | Even, Odd, None |
| Stop bits | 1 | 1, 2 |
| PLC sta. no. | 1 | 0–9 |
| Online simulator | YES | |
| Broadcast command | YES | |
| Extend address mode | YES |
PLC Settings
| Setting | Value |
|---|---|
| Communication mode | Modbus ASCII protocol |
Device Address
| Bit/Word | Device type | Format | Range | Memo |
|---|---|---|---|---|
| B | 1x | DDDDD | 1 ~ 65535 | Input bit (read only) |
| B | 0x | DDDDD | 1 ~ 65535 | Output bit |
| B | 3x_Bit | DDDDDdd | 100 ~ 6553515 | Input Register bit (read only) |
| B | 4x_Bit | DDDDDdd | 100 ~ 6553515 | Output Register bit |
| B | 6x_Bit | DDDDD | 100 ~ 6553515 | |
| W | 3x | DDDDD | 1 ~ 65535 | Input Register (read only) |
| W | 4x | DDDDD | 1 ~ 65535 | Output Register |
| W | 6x | DDDDD | 1 ~ 65535 | |
| DW | 3x_Double | DDDDD | 1 ~ 65535 | |
| DW | 4x_Double | DDDDD | 1 ~ 65535 |
NOTE: EBPro V6.03.02 or later supports 64-bit data type; the address limit range is 48 bits maximum.
Modbus ASCII Function Codes
| Device type | Read function | Write function |
|---|---|---|
0x | 0x01 Read coil | 0x05 Write single coil |
1x | 0x02 Read discrete input | N/A |
3x | 0x04 Read input register | N/A |
4x | 0x03 Read holding register | 0x10 Write multiple registers |
3x_Bit is equivalent to 3x. 4x_Bit is equivalent to 4x.
Wiring Diagrams
NOTE: The serial port pin assignments may vary between HMI models.
Diagram 1: RS-232
| HMI | Direction | PLC |
|---|---|---|
| Pin assignments | RS232 | |
| Rx | ↔ (bidirectional) | TXD |
| Tx | ↔ (bidirectional) | RXD |
| GND | ↔ (bidirectional) | GND |
| ↕︎ (tie) | RTS CTS |
Diagram 2: RS-485 4W
| HMI | Direction | PLC |
|---|---|---|
| Pin assignments | RS485 4W | |
| Rx- | ↔ (bidirectional) | Tx- |
| RX+ | ↔ (bidirectional) | Tx+ |
| Tx- | ↔ (bidirectional) | Rx- |
| Tx+ | ↔ (bidirectional) | Rx+ |
| GND | ↔ (bidirectional) | GND |
Diagram 3: RS-485 2W
| HMI | Direction | PLC |
|---|---|---|
| Pin assignments | RS485 2W | |
| Data- | ↔ (bidirectional) | D- |
| Data+ | ↔ (bidirectional) | D+ |
| GND | ↔ (bidirectional) | GND |
Website: www.modbus.org