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We have transferred a simple program based on  your code to a FMD PLC. When CR1 relay is turn on (use left mouse click during online monitoring), PWM1 and PWM2 (output 7 and did light up momentarily for duration set by your DELAY statement.

FMD PLC uses a different type of solid state output driver from T100MD888+.  Can you try to pull up the output 7 and 8 with a 1K ohm, 1/2W resistor and see if it makes a difference to the control action on your SSR.

Please also note that FMD8810 without the FRAM-RTC have some memory limitation (only DM[1] to DM[1000] are available), so make sure that it is not because your program is trying access on existent DM memory and therefore the program is not behaving as your have experienced in T100MD PLC.

What I mean by  ' no longer operates correctly ' is that when I operate the T100MD 888 with custom function :-
'
            'Set up control values for side shift
            '====================================
' set pwm level for side shift function & shift to 5th 


    setPWM 1,3500,500
    delay 10
    setPWM 1,9000,500
    delay 27
    setPWM 1,0,500
    delay 10
    setPWM 1,4500,500
    delay 5
    setPWM 1,4600,500
    delay 20
    setPWM 1,0,500
    delay 10
    setPWM 1,4600,500
    delay 20
    setPWM 1,3000,500
    setPWM 2,3500,500
    delay 30
    setPWM 1,3000,500
    setPWM 2,9000,500
    delay 100
    setPWM 1,0,5500
    setPWM 2,3500,500
    delay 2000
    setPWM 1,0,500
    setPWM 2,0,500
    delay 5000

the  outputs PWM1 ( Output 7 ) & PWM2 ( Output 8 ) work correctly and  switch the SSR's as per the custom function, but if I try to use
a FMD88-10 the same outputs only give a short duration pulse if anything at all.

Thnzk you for your help.
Yes we are using MODBUS RTU / RS485.
We will test the SETSYSTEM(3,0) instruction.

Hi All

I recently prototyped a project using PWM outputs on a T100MD 888  to operate two actuator solenoids on a truck gearbox, this works fine but when I replaced the T100 with an FMD88-10 The PWM outputs would no longer operate correctly. The outputs control two 100amp solid state relays so they aren't overloaded,  I tried another FMD88 with the same result.

Cheers Pete

Dear Tri_PLC
Doing some measurement with a scope we notice that the delay betwteen the request adress to the FMS and its answer is around 40 ms as it can be seen on the joined pic.
This capture show 3 requests adressed to 3 slaves, the FMD being the last one. The 2 first send answer within a few ms while FMD replies in 40 ms.
Any explanation or suggestion to reduce this delay that is well over the MODBUS protocole definition !
Thank you for your help.
Thierry