Siemens CP2433 ASI Master Problem

I have a Siemens CP2433 ASI Master module that is acting strange... The module normally scans 30 slaves, and each slave appears to scan without issue. However, every few scan cycles, the +10. +20, and +30 LEDs on the module illuminate at the same time, and the "Config Error" LED illuminates as well. After this, the module will scan normally for a cycle or two, but the "Config Error" and +10, +20, +30 simultaneous illumination again occurs.

If I stop the PLC and place the CP2433 in "Config" mode, the slaves scan normally, even after 10 minutes of observation. If I switch to "Protected" mode. the scan still is normal. After the PLC is started, the odd pattern described above returns.

I have reseated the CP2433 in the backplane, and then replaced the CP2433 without any change. The ASI power and Bus connections at the module are good, and the ASI voltage is 30 Volts. Any ideas what to do from here?

I havent done a 2433 but normally the leds on an asi module are pointing you to the fault or node

Have you looked in the manual for the 2433 (or online help) to diagnose what the leds are telling you ?

+10, +20, +30 all on together

If the CP 2433 is offline, the 3 group LEDs (10+, 20+, 30+) are all lit simultaneously.
During normal operation, this status only occurs briefly in the following situations:
- the power supply is switched on, or
- the PLC goes through a cold restart, or
- the mode selector is set to run while the PLC is in the STOP mode

Link to Manual (this may be the wrong manual as its for an S1 2433, although the config error should be the same)

Whats the CP2433 part number ?

Page 2-25 error diagnostics

CONFIG ERROR LED

Here, the CP2433 indicates whether the slave configuration detected on the AS-I cable matches the configuration stored on the CP (LPS). If they do not match, the CONFIG ERROR display is lit.
The CONFIG ERROR display is lit in the following situations:

• When a configured AS-I slave does not exist on the AS-I cable (e.g. fault on the slave).
• When a slave exists on the AS-I cable but has not been configured.
• When a connected slave has different configuration data (I/O configuration, ID code) from those configured on the CP. This means that an incorrect slave type on the AS-I cable can be detected (e.g. actuator instead of sensor).
• When the CP is in the offline phase.

I would suggest a faulty slave, this can be diagnosed (see 2-25 onwards) with step 7 and diagnostics

Thanks for the replies 504bloke. Unfortunately, the troublesome unit is on an S5 system with dual 928B CPUs and a coordinator card. Do you know off-hand if there are any diagnostics available with Step 5?

Looking at the manual i linked to, yes

You just need to follow page 2-12 onwards