I'm working in a project with a PLC (S7-300) and some MM440 with Profibus boards. I saw in this forum a topic "How do I read write / write parameters using Profibus on the MM4 ? " but I still have questions about write datas from PLC to Micromaster. So please, I need your help !
I configured in HW Config, 8 PZD inputs and 8 PZD outputs. In OB1 block the SFC14 and SFC15 are called. See below:
// Control word 1 + main setpoint to MM4
CALL "DPWR_DAT" (SFC15)
RECORD :=P#DB1.DBX 0.0 WORD 8
// Read 8 words of process data
CALL "DPRD_DAT" (SFC14)
RECORD :=P#DB1.DBX 16.0 WORD 8
I can understand the reading datas, because in the MM4 we have a parameter P2051
[page 2710 MM440] with 8 PZDs that can be configured, in other words, we have acess.
But I can't understand the writing datas, because we have 8 PZDs but these datas are not available (read only parameter) r2050 [page 2700].
So, I've configurated 8 words in my DB1 but don't I have acess to use these words ??
For example, If I need to chance the frequency several times during the process, for this writing differents values of frequencies on the second word (second PZD) - r2050. Is it possible ? How to do ??
Please, I'm very confused about it. On Masterdrive MC these parameters are available in words.
Sorry my english, it isn't my mother tongue.