FM350-1 starts counting from zero

Hi all,

Sorry for a newbie question, but I am really frustrated and need a quick idea.

I am using FM350-1 with CPU 315-2 PN/DP in Continuous count mode (actually representing a physical position of a moving part). I want to memorize its value in Retentive part of the memory and start counting from there next time it is started.

I have placed in OB100 the initial value load:
      L     288
      T     "CNT_CTRL".MOD_ADR
      L     P#288.0
      T     "CNT_CTRL".CH_ADR
      L     16
      T     "CNT_CTRL".U_D_LGTH
      L     "CurrentPosition"
      T     "CNT_CTRL".LOAD_VAL
    
      S     "CNT_7"

CNT2: CALL  CNT_CTL1
         DB_NO    :=1
         SW_GATE  :="CNT_1"
         GATE_STP :="CNT_2"
         OT_ERR_A :="CNT_3"
         SET_DO0  :="CNT_4"
         SET_DO1  :="CNT_5"
         OT_ERR   :="CNT_6"
         L_DIRECT :="CNT_7"
         L_PREPAR :="CNT_8"
         T_CMP_V1 :="CNT_9"
         T_CMP_V2 :="CNT_10"
         C_DOPARA :="CNT_11"
         RES_SYNC :="CNT_12"
         RES_ZERO :="CNT_13"
  
      A     "CNT_7"
      JC    CNT2
      L     "CNT_CTRL".ACT_CNTV
      T     "Test 1"

Monitoring of "Test 1" shows that the initial value is loaded correctly.

However, when I place the counter program into OB1, the loaded value is lost.

The counter starts counting correctly, but it always starts from zero.

What am I doing wrong? It must be something pretty obvious, but I am in complete frustration now :(

This is the counting piece of the program:

      L     288
      T     "CNT_CTRL".MOD_ADR
      L     P#288.0
      T     "CNT_CTRL".CH_ADR
      L     16
      T     "CNT_CTRL".U_D_LGTH

CNT4: CALL  CNT_CTL1
         DB_NO    :=1
         SW_GATE  :="CNT_1"
         GATE_STP :="CNT_2"
         OT_ERR_A :="CNT_3"
         SET_DO0  :="CNT_4"
         SET_DO1  :="CNT_5"
         OT_ERR   :="CNT_6"
         L_DIRECT :="CNT_7"
         L_PREPAR :="CNT_8"
         T_CMP_V1 :="CNT_9"
         T_CMP_V2 :="CNT_10"
         C_DOPARA :="CNT_11"
         RES_SYNC :="CNT_12"
         RES_ZERO :="CNT_13"

      L     "CNT_CTRL".ACT_CNTV
      T     "Test 2"
      L     "CNT_CTRL".ACT_CNTV
      T     "CurrentPosition"

Any idea will be appreciated! Thanks in advance.

Hello norvydas,

Perhaps the following link might help:

how can the counter values of compact CPUs and of the FM 350/FM450 counter module be made available again after a power failure?

Best regards,

Wizard

Hi,

here´s a similar FAQ how to retain the counter value of FM350-1:

https://support.industry.siemens.com/cs/de/en/view/30086528

Regards,

Towome