gefran 2500 Guide To Configuration And Network Installation

80018C_MSW_2400-2500-Profibus_1209_ENG
Page 9
4.5 DATA EXCHANGE (SAP DEFAULT)
After checking the correct instrument configuration and parameterisation via the telegrams described above, the
PROFIBUS Master activates the “DATA EXCHANGE” protocol in which it cyclically transmits some bytes in output
and reads some bytes in input to the PROFIBUS Slaves.
As mentioned above, there is an area of 7 bytes defined “Parametric Data” and an area of 32 bytes defined
“Process data” both in output and in input.
OUTPUT DATA
(from PROFIBUS Master to Slave)
PARAMETRIC
DATA
PROCESS DATA
“REQUEST” WORD 1 WORD 2 WORD 3 WORD 4 WORD 16
MSB LSB MSB LSB MSB LSB MSB LSB
≈
MSB LSB
1
2
3
4
5
6
7
8 9 10 11 12 13 14 15 38 39
INPUT DATA
(from PROFIBUS Slave to Master)
PARAMETRIC
DATA
PROCESS DATA
“REPLY” WORD 1 WORD 2 WORD 3 WORD 4 WORD 16
MSB LSB MSB LSB MSB LSB MSB LSB
≈
MSB LSB
1
2
3
4
5
6
7
8 9 10 11 12 13 14 15 38 39
“Parametric data” are “consistent” data that let you read or write any MODBUS variable, in both bit format and in
word format, in the 2400/2500 instruments connected to the PROFIBUS node.
PARAMETRIC DATA
BYTE
PARAMETER
DESCRIPTION
1 TRG TRIGGER BYTE: must be incremented by 1 at each new Request.
The Reply is correct only when the value is the same.
2 ADD SLAVE MODBUS address of 2400/2500 instrument (default = 1)
3 FC Function code to specify process: Bit/Word Read/Write
4 DATUM 1 Depends on FUNCTION CODE
5 DATUM 2 Depends on FUNCTION CODE
6 DATUM 3 Depends on FUNCTION CODE
7 DATUM 4 Depends on FUNCTION CODE
4.5.1 PARAMETRIC DATA: READING A BIT
Request bytes
TRG
ADD SLAVE
FC
ADD MSB
ADD LSB
NB MSB
NB LSB
Trigger Slave
Address
1 or 2 Address Bit to
read
Address Bit to
read
Number of bit
to read.
(always 00)
Number of bit
to read.
(always 01)
Reply bytes
TRG
ADD SLAVE
FC
NB
BIT
#
#
Reply to set
trigger
Confirm Slave
address
Confirm
process code.
(1 or 2)
Number of
bytes read
(always 1)
Value of bit:
0 or FF
Empty Empty

gefran 2500 Specifications

General

Brand	gefran
Model	2500
Category	Controller
Language	English