Siemens SIMATIC S5 Manual page 302

Error 12 (COM247: F8CH, PC: 12,) "correct MD - module number cannot be chan9ed"
As soon as the positioning module has at least one correct machine data record, the
module number can no longer be changed. The number already stored can be read in the
presets display of COM247 (=> Section 4.3.22 "Enter SYSID" and Section 2.5.6 "Other
Parameters").
Error22 (COM247: F96H, PC: 22) "processing more than one reach. prog. not
permitted"
This error occurs when an axis is creating a machining program in the teach-in mode and
you attempt to transfer, modify or delete a second machining program via the data
channel. It is also not possible to have more than one axis in the teach-in mode.
When the teach-in mode is active, only the JOG modes and incremental modes are
permitted. Input and transfer of machining programs is also not permitted.
If this error message appears, there is a hardware fault.
Error46 (COM247: FAEH, PC: 46) "illegal mode on this axis"
This message appears if you attempt to enter or delete a machining program on axes
data channel (axis 4) or to execute one of the operational modes 1...17 with the exception
of mode 17.
A machining program cannot be modified or deleted while it is being executed.
Error 52 (COM247: FB4H, PC: 52) "flying change could not be executed"
If this error occurs, one of the conditions of the flying change has not be met (=>
Section 2.6.6.3 "G1 O: Flying Change").
Error 53 (COM247: FB5H, PC: 53) "switch on power unit"
Each axis has a digital input with which the power unit can be monitored by the module.
This input must have a high signal when the power unit is switched on. If the power unit
does not have a "ready" contact, the ready signal must be simulated by jumpering wires
BBxL and BBx on the power unit.
(x = axis number).
Error 54 (COM247: FB6H, PC: 54) "error in ramp table generation"
This error occurs if it is not possible to generate an acceleration ramp with the
corresponding machine data. The combination of maximum frequency, start-stop
frequency and rate of frequency increase is not feasible.
Error 55 (COM247: F137H, PC: 55) 'PC failure"
If jumper X21 is connecting pins 2 and 3, the IP247 recognizes when the CPU outputs the
BASP signal (block command output). This error message terminates the traversing
movements on all three axes (=> Part 3 "Hardware").
Troubleshooting
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