Siemens Simatic S7-300, Инструкция по установке и эксплуатации

Страница: 284 / 356

Analog modules
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
Fail-safe signal modules
284
Installation and Operating Manual, 01/2010, A5E00085586-10
The following parameters of "HART_Gate" can be assigned:
●
"On": HART communication is enabled.
● "Can be switched": The HART communication can be activated and deactivated from the
safety program (
S7 Distributed Safety or S7 F Systems), provided the module is in RUN
mode. This means that the HART communication with HART field devices can be
activated and deactivated during operation of the F-CPU (e.g. for maintenance
purposes).
If you set the IPAR_EN variable of the F-I/O DB or of the F_CH_AI F-channel driver to "1"
in the safety program, HART communication is enabled for the module. If the setting is
"0", HART communication is disabled. The module acknowledges the enabled or disabled
HART communication with variable IPAR_OK = "1" or "0" in the F-I/O DB or in the
F_CH_AI F-channel driver.
Do not enable the HART communication until the status of your system allows the
parameters of the associated HART field device to be safely reassigned.
If you want to evaluate the "Enable HART communication" status in your safety program,
e.g., for the purpose of programming interlocks, you must generate the information as
follows:
Set (primarily) the "Enable HART communication" signal if you enable the HART
communication via IPAR_EN = 1. Reset the "Enable HART communication" signal with a
falling edge of the IPAR_OK variable.
This is necessary to ensure that the information is properly available even if
communication errors occur while the HART communication is enabled with
IPAR_EN = 1. Only change the status of IPAR_EN during this evaluation if there is no
passivation due to a communication error or F-I/O/channel fault (PASS_OUT = 0).
If you are using redundantly configured modules in
S7 F Systems, you must set the
IPAR_ENR variable of the F_CH_AI F-channel driver to "1" to enable the HART
communication to the redundant HART field device. The redundantly configured module
acknowledges the enabled or disabled HART communication with variable
IPAR_OK = "1" or "0" in the F_CH_AI F-channel driver.
WARNING
For module channels with HART devices
without write protection, the following applies
to an SIL 2/3 application: as soon as you open the HART_Gate, the input values of the
channels must be checked for plausibility, e.g. by performing a comparison with the
equivalent value of another module in the user program. Optionally, the module can also
be taken out of the safety function of the system for this time.
WARNING
Note that the opening of the HART_Gate is jumpered by a connected HART
communicator.