Sil2 A/D Conversion Function - Mitsubishi Electric R60AD8-G User Manual

10.8

SIL2 A/D Conversion Function

The R60AD8-G (Main) and R60AD8-G (Sub) use this function based on the time set in "SIL2 A/D conversion cycle setting" to
execute A/D conversion that satisfies the safety level defined by IEC61508: 2010 SIL2 and IEC61511: 2015 SIL2 while
executing error detection functions, such as double input discrepancy detection, and regular diagnostics for failure, such as A/
D conversion circuit diagnostics. The SIL2 diagnostic FB library is required for this function.
The following table describes each function executed by the SIL2 A/D conversion function, corresponding SIL2 diagnostic FB
library used, and the module status at the time of error detection.
Function name
Double input discrepancy
detection function
A/D conversion circuit
diagnostic function
Input HOLD function
SIL2 diagnostic FB library
Safety devices specified by the SIL2 diagnostic FB library and corresponding I/O labels are as follows.
■SIL2 safety program FB (M+SIL2ADG_ADConv_R)
• Symbol
M+SIL2ADG_ADConv_R
(1) B : i_bEN
(2) UW : i_u8ADRcvTbl
(3) B : i_bUnitErrClear
(4) B : i_bInitDiagSkip
• Input labels
No. Variable name
(1) i_bEN
10 FUNCTIONS
274
10.8 SIL2 A/D Conversion Function
SIL2 diagnostic FB library
used
SIL2 safety program FB
(M+SIL2ADG_ADConv_R)
• SIL2 safety program FB
(M+SIL2ADG_ADConv_R)
• SIL2 standard program FB
(M+SIL2ADG-
IEF_WriteDAVal_R)

o_bENO : B
o_u8ADSndTbl UW :
o_bOK : B
o_bErr : B
o_uErrId UW :
o_w8ADVal : W
o_uConnectSts UW :
o_u8DiagCode UW :
o_stNFB_ADConv DUT :
Name Data type
Execution command Bit
Module status at the time of error detection
Error description
Double input discrepancy
detection error (error code:
1EDH)
A/D conversion circuit diagnostic
error (error code: 1EFH)
Safety I/O HOLD time exceeded
error (error code: 1500H)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
Scope
On or off
Safety input status Relay connection
Input of a channel with Does not disconnect
an error turns off. sensors.
Disconnect sensors.
Previous values are The relay is not
maintained for input of changed.
all channels.
Description
On: The FB is activated.
Off: The FB is not activated.
Set 'Safety refresh communication status of each
safety connection (1st module)' (SA\SD1008 to
*1
SA\SD1015) for the intelligent device station where
the R60AD8-G (Main) is mounted.
For details on the safety special register, refer to the
following.
 MELSEC iQ-R CPU Module User's Manual
(Application)
For a setting example of this input label, refer to the
following.
Page 297 EXAMPLE OF OPERATION