IEC 61158-6-15:2010 pdf – lndustrial communication networks -Fieldbus specifications – Part 6-15: Application layer protocol specification -Type 15 elements
IEC 61158-6-15:2010 pdf – lndustrial communication networks -Fieldbus specifications – Part 6-15: Application layer protocol specification -Type 15 elements.
Allowed values: I to 247, and 0 for broadcast where supported.
NOTE In general the Unit ID is only required for logical devices having the role 01 servers. Otten logical devces can have either role or multiple rofes, vie configuration, and their Unit ID is not used when they Only perform In the client rote. Depending on the underlying layers some devices can have concurrently a client and a server role on the same access point, this is the case for clientiserver on Token BusIHDLC. outside the scope of this
This field represents:
a requested service, confirmed or unconfirmed, via an identifier called function code.
or the normal response and positive confirmation of a requested service, represented by
echoing the requested service identifier, or
— the exception response and negative confirmation of a requested service, represented by echoing the requested service identifier with its high bit turned on. The latter representation is also called exception.
Field Type: Unslgned8
220.127.116.11 Service id.ntifi.rs and function codes
Client/server service identifiers are commonly called function codes.
Function codes are encodings of services requested to a server Some function cees are further specialized by means of a sub-code, specified as part of the data fleld These encodings are partitioned In three categories, and since the subdivision may propagate to the sub-codes, for sake of completeness, despite being part of the data field they will also be mentioned here:
PublIcly assigned function codes
These function codes are either assigned to a standard service or reserved for future assignment. The standard services and their identifiers Will be detailed In this specification.
User definable function codes
These function codes can be used for experimentation in a controlled laboratory environment. They must not be used In an open environment.
Ranges: There are two ranges. FC 65 (0x41) to 72 (0x48) included, and 100 (0x64)to 110 (Ox6E) included
Reserved function codes
These function codes are currently used by some companies for legacy products and are not available for public use.
NOTE I Funchon code assignments are managed by the Modbus.IOA industrial consortium.
NOTE 2 The following function codes, while publicly assigned. are not covered by ttes specification: FC 7 (0*07.
Read Exception Statue), FC 6 (0x08. Diagnostics). FC II (0xOB. Get Corn Event Counter). FC 12 (OxOC. Get Corn
Event Log). FC 17(0*11, Report Slave ID).
NOTE 3 The folowing function codes arid (unction codelsub-codes are reserved FC 8119 (0x0810x13). FC 8121.
255 (OxO6fOxlS-OsFFFF), FC 9(0*09). FC 1O(OxOA), FC 13(0*00), FC 14 (OxOEt. FC 41 (0*29), FC 42 (Oic2AI, FC
4310.12 (Ox2BlOxOO.OxOC), FC 43115.255 IOv2BJOxOF.OxFF), FC 90 (QxSA), FC 91 (Qx5B), FC 125 (Ox7D), FC 126
(Ox7E). FC 127 (0x719.
In a normal response, the data octet count shows the quantity of octets to follow. incIudlig the FIFO queue count octets and the data octets.
The FIFO queue count is the quantity of data registers in the queue (not Including the FIFO queue count register itself).
The register data in the response parameter data elements is packed as two octets per register value, For each register, the first octet contains the high ocder register value bits and the second octet contains the low order register value bits (big.endian convention).
5.3.14 Broadcast Write Single Holding Register FAL PDU
18.104.22.168 R.qu.st prlmltlv.
Service identifier, function code = 6 (0x06); Unit ID = 0.
This funcbon code is used to write a single holding register In all the Unit ID addressable servers, by specifying Unit ID = 0.
This is an unconfirmed service.
The Request PDU specifies the address of the register to be written. Registers are addressed starting at zero- Therefore register numbered I is addressed as 0.
The register data in the request parameter data is packed as two octets per register. For each register, the first octet contains the high order register bits and the second octet contains the low order register bits (big-endian convention).
The format is given in Table 27.