Modbus driver for PCD-xx7 / S7 Master / Slave
Target: connection of Saia-Burgess PCD-xx7 or Siemens S7 to other PLC, PC, operator panels or other devices with MODBUS interface.
- GOULD - MODBUS in RTU form
- PCD /S7 is slave or master
- interface RS485, RS422, RS232 according to installed interface module in PCD / S7
- baudrate 300-38400 Baud (according to installed interface module)
- 7 / 8 data bits
- 1 / 2 stop bits
- Parity no / even / odd
- slave address 1...255
- CRC (cyclical redundancy check) with cyclical block check table,
check sum calculated with x16+x15+x2+1
- broadcast messages are only allowed for write functions 05, 06, 15, 16, no answer
- end of telegram with time-out detection of 3,5 x character time
Used system functions:
- SFC 245: initialization of serial interface PCD-xx7
- SFB 12 BSEND Send PCD-xx7, CP441
- SFB 13 BRCV Receive PCD-xx7, CP441
- SFC64 TIME_TCK System time
- function blocks for initialization of interface and data exchange with full
commentary, without knowhow protection for integration in your own software
- data blocks for CRC and function blocks. User can rename blocks.
Master and Slave Modbus drivers are available.
Multi-Master, Multislave or Master and Slave are possible with different interfaces.
Master: Read or write of coil or input (only read) status or registers in one
or more slaves. For example for reading or writing of datas from/to external devices or PLC.
Slave: Write coil status or registers to a master or read coil status or registers from master with automatical translation into PCD memory.
For example for reading or writing datas from/to a superior PLC, PC or an operator panel.
Ask for special versions, if required. Send your requiry to firstname.lastname@example.org.