Description of Function
This block cab be used to enable a GPRS connection and then transfer some information to the network server.
Configuration of Function
1) Timeout – If GPRS server does not respond within the set timeout period, the CPU will attempt the data transmission up to a maximum of three times after which the GPRS connection will be automatically disconnected. 2) Network Params – There are two options, see GPRS Connect for further information. 3) If your program has three VW with the following values: VW0 = 100
VW2 = 1000 VW4= 10000 The CPU will upload the VW0 to VW4 values to the server (Slave ID 1) as follows:
00 01 00 00 00 0D 01 10 00 00 00 03 06 00 64 03 E8 27 10
The request and response are prefixed by six bytes as follows: byte 0: transaction identifier - copied by server byte 1: transaction identifier - copied by server
byte 2: protocol identifier = 0 byte 3: protocol identifier = 0 byte 4: length field (upper byte) = 0 (since all messages are smaller than 256)
291
Made with FlippingBook - Online magazine maker