Siemens SIMATIC S5 Manual page 150

Data Transmission by Accessing Layer 2 Services
The procedures to follow for entering, modifying and transferring DB1 are described in detail in
section 1.4.
DB1 Parameters for Layer 2 Services
Parameter
Block ID: SL2:
STBS
STBR
Argument Permiss. range
n
MBx
MBy
* SAP 64 is the default SAP
** The next flag is reserved as length flag.
Retentive flags are also overwritten with 00
Example: Two S5-95Us communicating with each other using layer 2 services.
DB1 PLC 1
156: KS ='
168: KS =' BDR 500
180: KS ='5120
192: KS ='SDT 1 12
204: KS ='STBS 48 MB77
216: KS ='STBR 49 MB79
.
.
.
DB1 PLC 2
156: KS ='
168: KS =' BDR 500
180: KS ='5120
192: KS ='SDT 1 12
204: KS ='STBS 48 MB77
216: KS ='STBR 48 MB79
.
.
.
Once you have assigned the parameters, you must develop the control program for data
communications. You will learn how to do this in the next section.
8-10
Table 8-3. Layer 2 Services, DB1 Parameters
Argument
n MBx
n MBy
33 to 54, 64
*
1 to 253
1 to 253
on a cold PLC restart.
H
Table 8-4. Entering Parameters for Layer 2 Services
SL2: TLN 1 STA AKT';
HSA 10 TRT ';
SET 0 ST 400 ';
SDT 2 360 ';
';
';
SL2: TLN 2 STA AKT';
HSA 10 TRT ';
SET 0 ST 400 ';
SDT 2 360 ';
';
';
SAP number and location of the 'Send' status byte
SAP number and location of the 'Receive' status byte
Explanation
SAP number
Flag byte
Flag byte
Basic L2 parameters ( for description see 1.4)
Sending via SAP No. 48, 'Send' STB = FY 77;
Receiving via SAP No. 49,
'Receive' STB = FY 79
(FY 78 and 80 are reserved as length bytes)
Basic L2 parameters ( section 1.4)
Sending via SAP No. 48, 'Send' STB = FY 77;
Receiving via SAP No. 49,
'Receive' STB = FY 79
(FY 78 and 80 are reserved as length bytes)
S5-95U, SINEC L2
Meaning
SINEC L2
**
**
Explanation
EWA 4NEB 812 6112-02