Which driver does the AGP3300 use when the Shinko WCL is not in the device list?
The AGP3300-S1-D24-CA1M in GP Pro-EX 4.0 acts as the Modbus master, and the five Shinko Technos WCL-13A-SS/MM C5 controllers are Modbus slaves. A Shinko WCL entry is not needed. Select a generic Modbus serial master driver from the GP-Pro EX device/PLC selection list. Confirm the exact driver name in your installed GP-Pro EX; it varies with the driver package.
The generic driver only defines framing and address syntax. Register numbers, function code, scaling and byte order come from the WCL communication manual, not from GP-Pro EX.
Check before moving on: the driver is selected and the project builds with no unresolved device address errors. Nothing is proven on the wire yet.
Which serial settings must match on the HMI and all five controllers?
A Modbus RTU master and slave communicate only when baud rate, data bits, parity and stop bits are identical. Every slave on a multidrop segment also needs a unique station address. Use the WCL manual to find where each parameter is set. Start from this baseline on both sides:
| Parameter | Starting value | Where it must match |
|---|---|---|
| Baud rate | 19200 | HMI serial port and all five WCLs |
| Data bits | 8 | HMI and all five WCLs |
| Parity | None | HMI and all five WCLs |
| Stop bits | 1 | HMI and all five WCLs |
| Station address | Unique per controller | WCL setting must equal the HMI device address |
Eight data bits implies RTU framing. If the WCL manual lists ASCII or RTU as a selectable protocol, set RTU on the controller.
Check before moving on: write down the five station addresses and confirm no two match. A duplicate address makes two slaves answer one request and corrupts the reply.
How should the RS-485 path be wired from the HMI to the fifth controller?
The request leaves the HMI serial port, passes through any RS-485 conversion, and travels along a single bus that visits each controller in turn. Check the physical layer in this order:
- Read the WCL manual to confirm what the C5 option provides and which terminals carry A/B (or +/-). Confirm 2-wire or 4-wire.
- Wire in a daisy chain. Avoid star topologies and long stubs. Keep A-to-A and B-to-B polarity consistent; an A/B swap produces silence or framing errors, not a clean fault.
- Terminate at both physical ends of the bus and nowhere else. Disable or omit termination on the middle controllers.
- Provide bias so the idle line sits in a defined state. Use one bias source for the segment, as either the master port or the converter. If neither supplies it, add it externally.
Check before moving on: with power off, measure continuity of each conductor end to end and confirm no short between A and B. Confirm the shield is grounded at one point only.
How do I prove the PV register from a PC before touching the HMI?
Connect one WCL to a PC through an RS-485 adapter and poll it with a Modbus master tool such as modpoll. This isolates the register map from HMI configuration. Get the PV register number, the function code (holding or input register), the data type and the scaling from the WCL communication manual, then test:
modpoll -m rtu -b 19200 -d 8 -s 1 -p none -a <station> -r <PV_register> -c 1 -t 4 COM<n>Use -t 4 for holding registers or -t 3 for input registers, according to the manual. Modpoll addresses are 1-based by default; add -0 for zero-based addressing. Try both if the value is off by one register, since the manual may list either form.
| Result | Likely cause |
|---|---|
| Timeout, no reply | Wrong baud/parity, wrong station, A/B swapped, missing bias, adapter direction control |
| Illegal data address exception | Wrong register number or the 0/1 offset |
| Illegal function exception | Holding vs input register mismatch |
| Reply but value looks wrong | Decimal-point scaling, signed vs unsigned, or 32-bit word order |
Check before moving on: the polled value tracks the controller display at the controller. Change the process temperature or the display and confirm the register follows.
How do I define the PV tag in GP-Pro EX?
Copy the proven parameters into the HMI, not the reverse. In the GP-Pro EX device settings, enter the serial parameters from the table above and add one device per controller, each with its own station address. Then create the tag:
- Set the tag address to the register that modpoll returned correctly. Use the driver's address syntax and apply the same 0-based or 1-based offset that worked in the test.
- Match the data type to the register: 16-bit signed for a PV that can go negative, unsigned otherwise. For 32-bit values, select the word order that reproduced the correct number in the test.
- Apply scaling on the HMI. If the register returns tenths of a degree as an integer, divide in the display or tag so the numeric object shows the engineering value.
- Leave the timeout and retry settings at defaults first, then tune after the link is stable.
Poll time is bounded by the wire. Assumption: single-register reads. Five controllers and many tags each add to the scan cycle, so group tags on contiguous registers where the manual allows.
Check before moving on: one controller shows a live PV on the HMI that matches its own display.
How do I verify all five controllers end to end?
- Add the remaining four controllers to the bus one at a time. After each, confirm that its PV on the HMI matches its local display and that earlier controllers still read correctly.
- Force a fault by unplugging one controller. Confirm the HMI flags a communication error for that station only and the other four keep updating.
- Reconnect it and confirm the HMI recovers without a restart.
- Leave the system running through a full process cycle. Confirm there are no intermittent communication errors and the update rate meets your display needs.
- Change a real temperature on one controller and confirm the HMI value follows on that station and no other.
How do I read PV from a Shinko WCL on an AGP3300?
Use a generic Modbus serial master driver in GP-Pro EX, set the tag to the PV register listed in the WCL communication manual, and match the data type and scaling to it. Prove the register with modpoll from a PC first.
How do I set the communication parameters when the WCL is not in the device list?
Set the same baud rate, data bits, parity and stop bits on the HMI serial port and on each WCL; 19200, 8 data bits, no parity, 1 stop bit is a workable start. Give each controller a unique station address and enter that address on its HMI device entry.
How do I fix a timeout when the wiring looks correct?
Check A/B polarity, then termination at only the two bus ends and bias on the idle line. Then confirm parity, baud rate and station address on both sides, and retest a single slave from a PC with modpoll.