What it means
SINAMICS S120 and S150 raise the alarm A35231 "TM: Master control by PLC missing" when the "master control by PLC" signal was missing in operation. That signal normally reaches the drive from the higher-level control (the PLC) — either through the interconnection of binector input p0854 or across the fieldbus between master and drive — so the alarm points at this command link.
The alarm is only decisive in the "SIMOTION" operating mode (p4400 = 0). In the "SINAMICS" operating mode (p4400 = 1), the setpoints at p4420 are evaluated independent of binector input p0854.
Why it appears
- The binector input for "master control by PLC" is interconnected incorrectly (p0854).
- The higher-level control has withdrawn the "master control by PLC" signal.
- Data transfer via the fieldbus (master/drive) was interrupted.
What to check
- Check the interconnection of the binector input for "master control by PLC" (p0854).
- Check the "master control by PLC" signal and, if required, switch it in.
- Check the data transfer via the fieldbus (master/drive).
- Check the setting of parameter p2037.
Parameters the manual names
- p0854 — BI: Control by PLC/no control by PLC / Master ctrl by PLC. This is the binector input whose interconnection must carry the "master control by PLC" signal; it is the first place to look when A35231 appears.
- p4400 — TM41 encoder emulation operating mode / Enc_emulat mode. Decides whether this alarm is decisive at all: it is only decisive in the "SIMOTION" operating mode (p4400 = 0).
- p4420 — CI: TM41 encoder emulation position setpoint / Enc_emul s_set. In the "SINAMICS" operating mode (p4400 = 1) these setpoints are evaluated independent of binector input p0854.
- p2037 — IF1 PROFIdrive STW1.10 = 0 mode / IF1 PD STW1.10=0. The remedy for A35231 includes checking the setting of this parameter.
The same on every family
Every manual that describes A35231 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | — | — | Communication error to the higher-level control system (9) | None | SINAMICS S120, S150 List Manual · p. 3221 |
The drives this code lives on
A35231 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A35231 mean on a SINAMICS S120 or S150?
The drive raised A35231 "TM: Master control by PLC missing" because the "master control by PLC" signal was missing in operation. The manual names an incorrect interconnection of binector input p0854, withdrawal of the signal by the higher-level control, or an interrupted fieldbus transfer between master and drive as possible reasons.
When is alarm A35231 decisive?
Only in the "SIMOTION" operating mode (p4400 = 0). In the "SINAMICS" operating mode (p4400 = 1) the setpoints at p4420 are evaluated independent of binector input p0854.
How do I fix alarm A35231?
Check the interconnection of p0854, check the "master control by PLC" signal and switch it in if required, check the data transfer via the fieldbus (master/drive), and check the setting of p2037.
What is parameter p0854 used for here?
p0854 is the binector input (BI: Control by PLC/no control by PLC / Master ctrl by PLC) that carries the "master control by PLC" signal. A35231 is raised when that signal is missing in operation, so its interconnection is checked first.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the A35xxx group · SINAMICS manuals · Siemens manuals