A08555 — Modbus TCP: commissioning error

A08555 is an alarm that reports an incorrect setting for the Modbus TCP protocol. The consequence of the incorrect setting is that Modbus is not activated — or, for the setting reported with alarm value 1, that CBE20 is not activated. Which setting the drive is complaining about is shown by the alarm value it writes to r2124. The manuals describe the alarm in the same way for the G130/G150 and the S120/S150.

The drive raises A08555 because the Modbus TCP protocol cannot be commissioned with the current settings:

• Modbus is activated at the same time on the onboard interface (p2030) and on CBE20 (p8835), although CBE20 is not activated.
• No drive object supported by Modbus is available under p0978[0], so Modbus is not activated.
• The drive object SERVO with activated linear motor function (the FM bit LINMOT is set) is under p0978[0], so Modbus is not activated.

1. Read the alarm value in r2124 (interpret it as a decimal number) to identify which setting is incorrect.
2. For alarm value 1: check the parameterization of p2030 and p8835 and, if required, correct it.
3. For alarm value 2, and for alarm value 3 on the S120/S150: appropriately resort the list of drive objects in p0978 so that a drive object supported by Modbus stands under p0978[0]. The manuals differ here in one point: on the S120/S150 Modbus supports the drive objects SERVO (without linear motor) and VECTOR, on the G130/G150 only VECTOR.

The message value of the alarm is the alarm value, which the drive stores in r2124; interpret it as a decimal number:

• 1 — Modbus is activated simultaneously on the onboard interface (p2030) and CBE20 (p8835), and CBE20 is not activated.
• 2 — a drive object supported by Modbus is not available under p0978[0]; Modbus is not activated.
• 3 — the drive object SERVO is under p0978[0] and the FM bit LINMOT is set; the manual words this same condition a second time as: the drive object SERVO with activated linear motor function is under p0978[0]. Modbus is not activated.

• r2124 — holds the alarm value of A08555; read it as a decimal number to see which Modbus TCP setting is wrong.
• p2030 — field bus interface protocol selection: check here whether Modbus is activated on the onboard interface, and correct the setting for alarm value 1.
• p8835 — CBE20 firmware selection: check whether Modbus is activated on the CBE20 and correct it together with p2030 for alarm value 1.
• p0978 — list of drive objects: for alarm values 2 and 3, resort this list so that a drive object supported by Modbus stands under p0978[0].

No acknowledgement is required for A08555. Correcting the setting is the remedy itself: once p2030 and p8835 (alarm value 1) or the drive object list p0978 (alarm values 2 and 3) have been corrected, no separate reset step is needed.